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5784 lines (5741 loc) · 269 KB
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html lang="en" xml:lang="en" xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="content-type" content="text/html;charset=UTF-8"/>
<link rel="icon" type="image/gif" href="/favicon.gif"/>
<link rel="apple-touch-icon" sizes="120x120" href="touch-icon-iphone-retina.png" />
<link rel="apple-touch-icon" sizes="152x152" href="touch-icon-ipad-retina.png" />
<title>Scripting Languages I: Node.js, Python, PHP, Ruby - Hyperpolyglot</title>
<style type="text/css" id="internal-style">
@import url(hyperpolyglot.css);
</style>
<meta http-equiv="content-type" content="text/html;charset=UTF-8"/>
<meta http-equiv="content-language" content="en"/>
</head>
<body>
<div id="container-wrap-wrap">
<div id="container-wrap">
<div id="container">
<div id="header">
<h1><a href="/"><span>Hyperpolyglot</span></a></h1>
</div>
<div id="content-wrap">
<div id="main-content">
<div id="page-title">
Scripting Languages I: Node.js, Python, PHP, Ruby
</div>
<div id="page-content">
<p><a name="top" id="top"></a><em>a side-by-side reference sheet</em></p>
<p><strong>sheet one:</strong> <a href="#version">version</a> | <a href="#grammar-execution">grammar and execution</a> | <a href="#var-expr">variables and expressions</a> | <a href="#arithmetic-logic">arithmetic and logic</a> | <a href="#strings">strings</a> | <a href="#regexes">regexes</a> | <a href="#dates-time">dates and time</a> | <a href="#arrays">arrays</a> | <a href="#dictionaries">dictionaries</a> | <a href="#functions">functions</a> | <a href="#execution-control">execution control</a> | <a href="#exceptions">exceptions</a> | <a href="#threads">threads</a></p>
<p><strong><a href="/scripting2">sheet two</a>:</strong> <a href="/scripting2#streams">streams</a> | <a href="/scripting2#async">asynchronous events</a> | <a href="/scripting2#files">files</a> | <a href="/scripting2#file-fmt">file formats</a> | <a href="/scripting2#directories">directories</a> | <a href="/scripting2#processes-environment">processes and environment</a> | <a href="/scripting2#option-parsing">option parsing</a> | <a href="/scripting2#libraries-namespaces">libraries and namespaces</a> | <a href="/scripting2#objects">objects</a> | <a href="/scripting2#reflection">reflection</a> | <a href="/scripting2#net-web">net and web</a> | <a href="/scripting2#databases">databases</a> | <a href="/scripting2#unit-tests">unit tests</a> | <a href="/scripting2#debugging">debugging</a></p>
<table class="wiki-content-table">
<tr>
<th colspan="5"><a name="version" id="version"></a><a href="#version-note">version</a></th>
</tr>
<tr>
<th></th>
<th>node.js</th>
<th>python</th>
<th>php</th>
<th>ruby</th>
</tr>
<tr>
<td><a name="version-used" id="version-used"></a><a href="#version-used-note">version used</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><em>6.11</em></span></td>
<td><span style="color: gray"><em>3.6</em></span></td>
<td><span style="color: gray"><em>7.0</em></span></td>
<td><span style="color: gray"><em>2.3</em></span></td>
</tr>
<tr>
<td><a name="version" id="version"></a><a href="#version-note">show version</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>$ node <span style="white-space: pre-wrap;">--</span>version</td>
<td>$ python -V<br />
$ python <span style="white-space: pre-wrap;">--</span>version</td>
<td>$ php <span style="white-space: pre-wrap;">--</span>version</td>
<td>$ ruby <span style="white-space: pre-wrap;">--</span>version</td>
</tr>
<tr>
<td><a name="implicit-prologue" id="implicit-prologue"></a><a href="#implicit-prologue-note">implicit prologue</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><span style="white-space: pre-wrap;">//</span> npm install lodash</span><br />
const _ = require('lodash');</td>
<td>import os, re, sys</td>
<td><span style="color: gray"># sudo apt install php-mbstring</span></td>
<td><span style="color: gray"><em>none</em></span></td>
</tr>
<tr>
<th colspan="5"><a name="grammar-execution" id="grammar-execution"></a><a href="#grammar-execution-note">grammar and execution</a></th>
</tr>
<tr>
<th></th>
<th>node.js</th>
<th>python</th>
<th>php</th>
<th>ruby</th>
</tr>
<tr>
<td><a name="interpreter" id="interpreter"></a><a href="#interpreter-note">interpreter</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>$ node foo.js</td>
<td>$ python foo.py</td>
<td>$ php -f foo.php</td>
<td>$ ruby foo.rb</td>
</tr>
<tr>
<td><a name="repl" id="repl"></a><a href="#repl-note">repl</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>$ node</td>
<td>$ python</td>
<td>$ php -a</td>
<td>$ irb</td>
</tr>
<tr>
<td><a name="cmd-line-program" id="cmd-line-program"></a><a href="#cmd-line-program-note">command line program</a></td>
<td>$ node -e "console.log('hi!');"</td>
<td>$ python -c 'print("hi!")'</td>
<td>$ php -r 'echo "hi!\n";'</td>
<td>$ ruby -e 'puts "hi!"'</td>
</tr>
<tr>
<td><a name="block-delimiters" id="block-delimiters"></a><a href="#block-delimiters-note">block delimiters</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>{}</td>
<td>: <span style="color: gray"><em>and offside rule</em></span></td>
<td>{}</td>
<td>{}<br />
do end</td>
</tr>
<tr>
<td><a name="statement-separator" id="statement-separator"></a><a href="#statement-separator-note">statement separator</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><em>; or newline<br />
<br />
newline not separator inside (), [], {}, "", '', or after binary operator<br />
<br />
newline sometimes not separator when following line would not parse as a valid statement</em></span></td>
<td><span style="color: gray"><em>newline or</em></span> ;<br />
<br />
<span style="color: gray"><em>newlines not separators inside (), [], {}, triple quote literals, or after backslash: <span style="white-space: pre-wrap;">\</span></em></span></td>
<td>;<br />
<br />
<span style="color: gray"><em>statements must be semicolon terminated inside {}</em></span></td>
<td><span style="color: gray"><em>newline or</em></span> ;<br />
<br />
<span style="color: gray"><em>newlines not separators inside (), [], {}, <span style="white-space: pre-wrap;">``</span>, '', "", or after binary operator or backslash: <span style="white-space: pre-wrap;">\</span></em></span></td>
</tr>
<tr>
<td><a name="source-code-encoding" id="source-code-encoding"></a><a href="#source-code-encoding-note">source code encoding</a></td>
<td><span style="color: gray"><em>source is always UTF-8</em></span></td>
<td><span style="color: gray"><em>Python 3 source is UTF-8 by default; Python 2 source is US-ASCII</em></span><br />
<br />
<span style="color: gray"># -*- coding: us-ascii -*-</span></td>
<td><span style="color: gray"><em>none</em></span></td>
<td><span style="color: gray"><em>Ruby 2.0 source is UTF-8 by default</em></span><br />
<br />
<span style="color: gray"># -*- coding: utf-8 -*-</span></td>
</tr>
<tr>
<td><a name="eol-comment" id="eol-comment"></a><a href="#eol-comment-note">end-of-line comment</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><span style="white-space: pre-wrap;">//</span> comment</span></td>
<td><span style="color: gray"># comment</span></td>
<td><span style="color: gray"><span style="white-space: pre-wrap;">//</span> comment<br />
# comment</span></td>
<td><span style="color: gray"># comment</span></td>
</tr>
<tr>
<td><a name="multiple-line-comment" id="multiple-line-comment"></a><a href="#multiple-line-comment-note">multiple line comment</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray">/* line<br />
another line */</span></td>
<td><span style="color: gray"><em>use triple quote string literal:</em></span><br />
<br />
'''comment line<br />
another line'''</td>
<td><span style="color: gray">/* comment line<br />
another line */</span></td>
<td><span style="color: gray">=begin<br />
comment line<br />
another line<br />
=end</span></td>
</tr>
<tr>
<th colspan="5"><a name="var-expr" id="var-expr"></a><a href="#var-expr-note">variables and expressions</a></th>
</tr>
<tr>
<th></th>
<th>node.js</th>
<th>python</th>
<th>php</th>
<th>ruby</th>
</tr>
<tr>
<td><a name="local-var" id="local-var"></a><a href="#local-var-note">local variable</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><span style="white-space: pre-wrap;">//</span> new in ES6:</span><br />
let x = 1;<br />
let y = 2, z = 3;<br />
<br />
<span style="color: gray"><span style="white-space: pre-wrap;">//</span> older alternative to let:</span><br />
var x = 1;<br />
<br />
<span style="color: gray"><span style="white-space: pre-wrap;">//</span> let local scope is nearest<br />
<span style="white-space: pre-wrap;">//</span> enclosing block; var local scope<br />
<span style="white-space: pre-wrap;">//</span> is nearest function body.<br />
<br />
<span style="white-space: pre-wrap;">//</span> var variables are visible to all code<br />
<span style="white-space: pre-wrap;">//</span> in the function body; even code<br />
<span style="white-space: pre-wrap;">//</span> preceding the var statement.</span></td>
<td><span style="color: gray"># in function body:</span><br />
x = 1<br />
y, z = 2, 3</td>
<td><span style="color: gray"># in function body:</span><br />
$x = 1;<br />
list($y, $z) = [2, 3];</td>
<td>x = 1<br />
y, z = 2, 3</td>
</tr>
<tr>
<td><a name="file-scope-var" id="file-scope-var"></a><a href="#file-scope-var-note">file scope variable</a></td>
<td><span style="color: gray"><span style="white-space: pre-wrap;">//</span> outside any function body:</span><br />
let n = 1;<br />
<br />
incrFileVar () { n++; }</td>
<td><span style="color: gray"><em>none</em></span></td>
<td><span style="color: gray"><em>none</em></span></td>
<td><span style="color: gray"><em>none</em></span></td>
</tr>
<tr>
<td><a name="global-var" id="global-var"></a><a href="#global-var-note">global variable</a></td>
<td>global.g = 1;<br />
<br />
incrGlobal () { global.g++; }</td>
<td>g = 1<br />
<br />
def incr_global():<br />
<span style="white-space: pre-wrap;"> </span>global g<br />
<span style="white-space: pre-wrap;"> </span>g += 1</td>
<td>$g = 1;<br />
<br />
function incr_global() {<br />
<span style="white-space: pre-wrap;"> </span>global $g;<br />
<span style="white-space: pre-wrap;"> </span>++$g;<br />
}</td>
<td>$g = 1<br />
<br />
def incr_global<br />
<span style="white-space: pre-wrap;"> </span>$g += 1<br />
end</td>
</tr>
<tr>
<td><a name="const" id="const"></a><a href="#const-note">constant</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><span style="white-space: pre-wrap;">//</span> new in ES6</span><br />
const PI = 3.14;</td>
<td><span style="color: gray"># uppercase identifiers<br />
# constant by convention</span><br />
PI = 3.14</td>
<td>define("PI", 3.14);<br />
<br />
const PI = 3.14;</td>
<td><span style="color: gray"># warning if capitalized<br />
# identifier is reassigned</span><br />
PI = 3.14</td>
</tr>
<tr>
<td><a name="assignment" id="assignment"></a><a href="#assignment-note">assignment</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>v = 1;</td>
<td><span style="color: gray"># assignments can be chained<br />
# but otherwise don't return values:</span><br />
v = 1</td>
<td>$v = 1;</td>
<td>v = 1</td>
</tr>
<tr>
<td><a name="parallel-assignment" id="parallel-assignment"></a><a href="#parallel-assignment-note">parallel assignment</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><span style="white-space: pre-wrap;">//</span> new in ES6:</span><br />
let [x, y, z] = [1, 2, 3];</td>
<td>x, y, z = 1, 2, 3<br />
<br />
<span style="color: gray"># raises ValueError:</span><br />
x, y = 1, 2, 3<br />
<br />
<span style="color: gray"># raises ValueError:</span><br />
x, y, z = 1, 2</td>
<td>list($x, $y, $z) = [1 ,2, 3];<br />
<br />
<span style="color: gray"># 3 is discarded:</span><br />
list($x, $y) = [1, 2, 3];<br />
<br />
<span style="color: gray"># $z set to NULL:</span><br />
list($x, $y, $z) = [1, 2];</td>
<td>x, y, z = 1, 2, 3<br />
<br />
<span style="color: gray"># 3 is discarded:</span><br />
x, y = 1, 2, 3<br />
<br />
<span style="color: gray"># z set to nil:</span><br />
x, y, z = 1, 2</td>
</tr>
<tr>
<td><a name="swap" id="swap"></a><a href="#swap-note">swap</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><span style="white-space: pre-wrap;">//</span> new in ES6:</span><br />
[x, y] = [y, x];</td>
<td>x, y = y, x</td>
<td>list($x, $y) = [$y, $x];</td>
<td>x, y = y, x</td>
</tr>
<tr>
<td><a name="compound-assignment" id="compound-assignment"></a><a href="#compound-assignment-note">compound assignment</a><br />
<span style="color: gray"><em>arithmetic, string, logical, bit</em></span></td>
<td>+= -= *= /= <span style="color: gray"><em>none</em></span> %=<br />
+=<br />
<span style="color: gray"><em>none</em></span><br />
<span style="white-space: pre-wrap;"><<= >>= </span>&= |= ^=</td>
<td><span style="color: gray"># do not return values:</span><br />
+= -= *= /= <span style="white-space: pre-wrap;">//</span>= %= <span style="white-space: pre-wrap;">**</span>=<br />
+= *=<br />
&= <span style="white-space: pre-wrap;">|</span>= ^=<br />
<span style="white-space: pre-wrap;"><<= >>= </span>&= |= ^=</td>
<td>+= -= *= <span style="color: gray"><em>none</em></span> /= %= <span style="white-space: pre-wrap;">**</span>=<br />
.= <span style="color: gray"><em>none</em></span><br />
&= |= <span style="color: gray"><em>none</em></span><br />
<span style="white-space: pre-wrap;"><<= >>= </span>&= |= ^=</td>
<td>+= -= *= /= <span style="color: gray"><em>none</em></span> %= <span style="white-space: pre-wrap;">**</span>=<br />
+= *=<br />
&&= <span style="white-space: pre-wrap;">||</span>= ^=<br />
<span style="white-space: pre-wrap;"><<= >>= </span>&= |= ^=</td>
</tr>
<tr>
<td><a name="incr-decr" id="incr-decr"></a><a href="#incr-decr-note">increment and decrement</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>let x = 1;<br />
let y = ++x;<br />
let z = <span style="white-space: pre-wrap;">--</span>y;</td>
<td><span style="color: gray"><em>none</em></span></td>
<td>$x = 1;<br />
$y = ++$x;<br />
$z = <span style="white-space: pre-wrap;">--</span>$y;</td>
<td>x = 1<br />
<span style="color: gray"># x and y not mutated:</span><br />
y = x.succ<br />
z = y.pred</td>
</tr>
<tr>
<td><a name="null" id="null"></a><a href="#null-note">null</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>null</td>
<td>None</td>
<td>NULL <span style="color: gray"># case insensitive</span></td>
<td>nil</td>
</tr>
<tr>
<td><a name="null-test" id="null-test"></a><a href="#null-test-note">null test</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>v === null</td>
<td>v is None</td>
<td>is_null($v)<br />
! isset($v)</td>
<td>v == nil<br />
v.nil?</td>
</tr>
<tr>
<td><a name="undef-var" id="undef-var"></a><a href="#undef-var-note">undefined variable</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><em>Evaluates as</em></span> undefined<br />
<br />
<span style="color: gray"><em>Use the triple equality</em></span> === <span style="color: gray"><em>operator to test for this value.</em></span></td>
<td><span style="color: gray"><em>raises</em></span> NameError</td>
<td><span style="color: gray"><em>Evaluates as</em></span> NULL</td>
<td><span style="color: gray"><em>raises</em></span> NameError</td>
</tr>
<tr>
<td><a name="conditional-expr" id="conditional-expr"></a><a href="#conditional-expr-note">conditional expression</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>x > 0 ? x : -x</td>
<td>x if x > 0 else -x</td>
<td>$x > 0 ? $x : -$x</td>
<td>x > 0 ? x : -x</td>
</tr>
<tr>
<th colspan="5"><a name="arithmetic-logic" id="arithmetic-logic"></a><a href="#arithmetic-logic-note">arithmetic and logic</a></th>
</tr>
<tr>
<th></th>
<th>node.js</th>
<th>python</th>
<th>php</th>
<th>ruby</th>
</tr>
<tr>
<td><a name="true-false" id="true-false"></a><a href="#true-false-note">true and false</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>true false</td>
<td>True False</td>
<td>TRUE FALSE <span style="color: gray"># case insensitive</span></td>
<td>true false</td>
</tr>
<tr>
<td><a name="falsehoods" id="falsehoods"></a><a href="#falsehoods-note">falsehoods</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>false null undefined '' 0 NaN</td>
<td>False None 0 0.0 '' [] {}</td>
<td>FALSE NULL 0 0.0 "" "0" []</td>
<td>false nil</td>
</tr>
<tr>
<td><a name="logical-op" id="logical-op"></a><a href="#logical-op-note">logical operators</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="white-space: pre-wrap;">&& ||</span> !</td>
<td>and or not</td>
<td>&& <span style="white-space: pre-wrap;">||</span> !<br />
<span style="color: gray"><em>lower precedence:</em></span><br />
and or xor</td>
<td>&& <span style="white-space: pre-wrap;">||</span> !<br />
<span style="color: gray"><em>lower precedence:</em></span><br />
and or not</td>
</tr>
<tr>
<td><a name="relational-op" id="relational-op"></a><a href="#relational-op-note">relational operators</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="white-space: pre-wrap;">===</span> !== < > >= <=<br />
<br />
<span style="color: gray"><em>perform type coercion:</em></span><br />
<span style="white-space: pre-wrap;">==</span> !=</td>
<td><span style="color: gray"><em>relational operators are chainable:</em></span><br />
== != > < >= <=</td>
<td>== != <span style="color: gray"><em>or</em></span> <> > < >= <=<br />
<span style="color: gray"><em>no conversion:</em></span> === !==</td>
<td>== != > < >= <=</td>
</tr>
<tr>
<td><a name="min-max" id="min-max"></a><a href="#min-max-note">min and max</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>Math.min(1, 2, 3)<br />
Math.max(1, 2, 3)<br />
<br />
Math.min.apply(Math, [1, 2, 3])<br />
Math.max.apply(Math, [1, 2, 3])</td>
<td>min(1, 2, 3)<br />
max(1, 2, 3)<br />
<br />
min([1, 2, 3])<br />
max([1, 2, 3])</td>
<td>min(1, 2, 3)<br />
max(1, 2, 3)<br />
$a = [1, 2, 3]<br />
min($a)<br />
max($a)</td>
<td>[1, 2, 3].min<br />
[1, 2, 3].max</td>
</tr>
<tr>
<td><a name="arith-op" id="arith-op"></a><a href="#arith-op-note">arithmetic operators</a><br />
<span style="color: gray"><em>addition, subtraction, multiplication, float division, quotient, remainder</em></span></td>
<td>+ - * / <span style="color: gray"><em>none</em></span> %</td>
<td>+ - * / // %<br />
<br />
<span style="color: gray"><em>In Python 2, / performs integer division.</em></span></td>
<td>+ - * / <span style="color: gray"><em>none</em></span> %</td>
<td>+ - * x.fdiv(y) / %</td>
</tr>
<tr>
<td><a name="int-div" id="int-div"></a><a href="#int-div-note">integer division</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>Math.floor(22 / 7)</td>
<td>22 // 7</td>
<td>(int)(22 / 7)</td>
<td>22 / 7</td>
</tr>
<tr>
<td><a name="divmod" id="divmod"></a><a href="#divmod-note">divmod</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><em>none</em></span></td>
<td>q, r = divmod(22, 7)</td>
<td><span style="color: gray"><em>none</em></span></td>
<td>q, r = 22.divmod(7)</td>
</tr>
<tr>
<td><a name="int-div-zero" id="int-div-zero"></a><a href="#int-div-zero-note">integer division by zero</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><em>Returns Infinity, NaN, or -Infinity depending upon sign of dividend.<br />
<br />
There are literals for Infinity and NaN.</em></span></td>
<td><span style="color: gray"><em>raises</em> ZeroDivisionError</span></td>
<td><span style="color: gray"><em>returns</em> FALSE <em>with warning</em></span></td>
<td><span style="color: gray"><em>raises</em> ZeroDivisionError</span></td>
</tr>
<tr>
<td><a name="float-div" id="float-div"></a><a href="#float-div-note">float division</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>22 / 7</td>
<td>22 / 7<br />
<br />
<span style="color: gray"># Python 2:</span><br />
float(22) / 7</td>
<td>22 / 7</td>
<td>22.to_f / 7<br />
<br />
22.fdiv(7)</td>
</tr>
<tr>
<td><a name="float-div-zero" id="float-div-zero"></a><a href="#float-div-zero-note">float division by zero</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><em>same behavior as for integers</em></span></td>
<td><span style="color: gray"><em>raises</em> ZeroDivisionError</span></td>
<td><span style="color: gray"><em>returns</em> FALSE <em>with warning</em></span></td>
<td><span style="color: gray"><em>returns</em> -Infinity, NaN, <em>or</em> Infinity</span></td>
</tr>
<tr>
<td><a name="power" id="power"></a><a href="#power-note">power</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>Math.pow(2, 32)</td>
<td>2 <span style="white-space: pre-wrap;">**</span> 32</td>
<td>pow(2, 32)</td>
<td>2 <span style="white-space: pre-wrap;">**</span> 32</td>
</tr>
<tr>
<td><a name="sqrt" id="sqrt"></a><a href="#sqrt-note">sqrt</a></td>
<td>Math.sqrt(2)</td>
<td>import math<br />
<br />
math.sqrt(2)</td>
<td>sqrt(2)</td>
<td>include Math<br />
<br />
sqrt(2)</td>
</tr>
<tr>
<td><a name="sqrt-negative-one" id="sqrt-negative-one"></a><a href="#sqrt-negative-one-note">sqrt -1</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>NaN</td>
<td><span style="color: gray"># raises ValueError:</span><br />
import math<br />
math.sqrt(-1)<br />
<br />
<span style="color: gray"># returns complex float:</span><br />
import cmath<br />
cmath.sqrt(-1)</td>
<td>NaN</td>
<td><span style="color: gray">Math.sqrt(-1) raises Math::DomainError unless require 'complex' is in effect.</span><br />
<br />
<span style="color: gray">(-1) ** 0.5 is (0+1.0i)</span></td>
</tr>
<tr>
<td><a name="transcendental-func" id="transcendental-func"></a><a href="#transcendental-func-note">transcendental functions</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>Math.exp Math.log Math.sin Math.cos Math.tan Math.asin Math.acos Math.atan Math.atan2</td>
<td>from math import exp, log, \<br />
sin, cos, tan, asin, acos, atan, atan2</td>
<td>exp log sin cos tan asin acos atan atan2</td>
<td>include Math<br />
<br />
exp log sin cos tan asin acos atan atan2</td>
</tr>
<tr>
<td><a name="transcendental-const" id="transcendental-const"></a><a href="#transcendental-const-note">transcendental constants</a><br />
<span style="color: gray"><em>π and e</em></span></td>
<td>Math.PI<br />
Math.E</td>
<td>import math<br />
<br />
math.pi math.e</td>
<td>M_PI M_E</td>
<td>include Math<br />
<br />
PI E</td>
</tr>
<tr>
<td><a name="float-truncation" id="float-truncation"></a><a href="#float-truncation-note">float truncation</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><em>none</em></span><br />
Math.round(3.1)<br />
Math.floor(3.1)<br />
Math.ceil(3.1)</td>
<td>import math<br />
<br />
int(x)<br />
int(round(x))<br />
math.ceil(x)<br />
math.floor(x)</td>
<td>(int)$x<br />
round($x)<br />
ceil($x)<br />
floor($x)</td>
<td>x.to_i<br />
x.round<br />
x.ceil<br />
x.floor</td>
</tr>
<tr>
<td><a name="abs-val" id="abs-val"></a><a href="#abs-val-note">absolute value</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>Math.abs(-3)</td>
<td>abs(x)</td>
<td>abs($x)</td>
<td>x.abs</td>
</tr>
<tr>
<td><a name="int-overflow" id="int-overflow"></a><a href="#int-overflow-note">integer overflow</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><em>all numbers are floats</em></span></td>
<td><span style="color: gray"><em>becomes arbitrary length integer of type</em> long</span></td>
<td><span style="color: gray"><em>converted to float</em></span></td>
<td><span style="color: gray"><em>becomes arbitrary length integer of type</em> Bignum</span></td>
</tr>
<tr>
<td><a name="float-overflow" id="float-overflow"></a><a href="#float-overflow-note">float overflow</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>Infinity</td>
<td><span style="color: gray"><em>raises</em> OverflowError</span></td>
<td>INF</td>
<td>Infinity</td>
</tr>
<tr>
<td><a name="rational-construction" id="rational-construction"></a><a href="#rational-construction-note">rational construction</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><em>none</em></span></td>
<td>from fractions import Fraction<br />
<br />
x = Fraction(22, 7)</td>
<td><span style="color: gray"><em>none</em></span></td>
<td>22 / 7r<br />
22r / 7</td>
</tr>
<tr>
<td><a name="rational-decomposition" id="rational-decomposition"></a><a href="#rational-decomposition-note">rational decomposition</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><em>none</em></span></td>
<td>x.numerator<br />
x.denominator</td>
<td><span style="color: gray"><em>none</em></span></td>
<td>(22 / 7r).numerator<br />
(22 / 7r).denominator</td>
</tr>
<tr>
<td><a name="complex-construction" id="complex-construction"></a><a href="#complex-construction-note">complex construction</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><em>none</em></span></td>
<td>z = 1 + 1.414j</td>
<td><span style="color: gray"><em>none</em></span></td>
<td>z = 1 + 1.414i</td>
</tr>
<tr>
<td><a name="complex-decomposition" id="complex-decomposition"></a><a href="#complex-decomposition-note">complex decomposition</a><br />
<span style="color: gray"><em>real and imaginary component, argument, absolute value, conjugate</em></span></td>
<td><span style="color: gray"><em>none</em></span></td>
<td>import cmath<br />
<br />
z.real<br />
z.imag<br />
cmath.phase(z)<br />
abs(z)<br />
z.conjugate()</td>
<td><span style="color: gray"><em>none</em></span></td>
<td>(1 + 3i).real<br />
(1 + 3i).imag<br />
(1 + 3i).arg<br />
(1 + 3i).abs<br />
(1 + 3i).conj</td>
</tr>
<tr>
<td><a name="random-num" id="random-num"></a><a href="#random-num-note">random number</a><br />
<span style="color: gray"><em>uniform integer, uniform float, normal float</em></span></td>
<td>Math.floor(Math.random() * 100)<br />
Math.random()<br />
<span style="color: gray"><em>none</em></span></td>
<td>import random<br />
<br />
random.randint(0, 99)<br />
random.random()<br />
random.gauss(0, 1)</td>
<td>rand(0,99)<br />
lcg_value()<br />
<span style="color: gray"><em>none</em></span></td>
<td>rand(100)<br />
rand<br />
<span style="color: gray"><em>none</em></span></td>
</tr>
<tr>
<td><a name="random-seed" id="random-seed"></a><a href="#random-seed-note">random seed</a><br />
<span style="color: gray"><em>set, get, restore</em></span></td>
<td><span style="color: gray"><em>none</em></span></td>
<td>import random<br />
<br />
random.seed(17)<br />
seed = random.getstate()<br />
random.setstate(seed)</td>
<td>srand(17);<br />
<br />
<span style="color: gray"><em>none</em></span></td>
<td>srand(17)<br />
<br />
seed = srand<br />
srand(seed)</td>
</tr>
<tr>
<td><a name="bit-op" id="bit-op"></a><a href="#bit-op-note">bit operators</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="white-space: pre-wrap;"><< >> & | ^ ~</span></td>
<td><span style="white-space: pre-wrap;"><< >> & | ^ ~</span></td>
<td><span style="white-space: pre-wrap;"><< >> & | ^ ~</span></td>
<td><span style="white-space: pre-wrap;"><< >> & | ^ ~</span></td>
</tr>
<tr>
<td><a name="binary-octal-hex-literals" id="binary-octal-hex-literals"></a><a href="#binary-octal-hex-literals-note">binary, octal, and hex literals</a></td>
<td><span style="color: gray"><em>none</em></span><br />
052 <span style="color: gray"><span style="white-space: pre-wrap;">//</span> deprecated</span><br />
0x2a</td>
<td>0b101010<br />
0o52<span style="white-space: pre-wrap;"> </span><span style="color: gray"><span style="white-space: pre-wrap;">#</span> also 052 in Python 2</span><br />
0x2a</td>
<td>0b101010<br />
052<br />
0x2a</td>
<td>0b101010<br />
052<br />
0x2a</td>
</tr>
<tr>
<td><a name="radix" id="radix"></a><a href="#radix-note">radix</a><br />
<span style="color: gray"><em>convert integer to and from string with radix</em></span></td>
<td>(42).toString(7)<br />
parseInt('60', 7)</td>
<td><span style="color: gray"><em>none</em></span><br />
int('60', 7)</td>
<td>base_convert("42", 10, 7);<br />
base_convert("60", 7, 10);</td>
<td>42.to_s(7)<br />
"60".to_i(7)</td>
</tr>
<tr>
<th colspan="5"><a name="strings" id="strings"></a><a href="#strings-note">strings</a></th>
</tr>
<tr>
<th></th>
<th>node.js</th>
<th>python</th>
<th>php</th>
<th>ruby</th>
</tr>
<tr>
<td><a name="str-type" id="str-type"></a><a href="#str-type-note">string type</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>String</td>
<td>str<br />
<br />
<span style="color: gray"># Python 2:</span><br />
unicode</td>
<td><span style="color: gray"># array of bytes:</span><br />
string</td>
<td>String</td>
</tr>
<tr>
<td><a name="str-literal" id="str-literal"></a><a href="#str-literal-note">string literal</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>'don\'t say "no"'<br />
"don't say \"no\""</td>
<td>'don\'t say "no"'<br />
"don't say \"no\""<br />
"don't " 'say "no"'<br />
<br />
<span style="color: gray"># Python 2 (and Python 3):</span><br />
u'lorem'<br />
u"ipsum"</td>
<td>"don't say \"no\""<br />
'don\'t say "no"'</td>
<td>"don't say \"no\""<br />
'don\'t say "no"'<br />
"don't " 'say "no"'</td>
</tr>
<tr>
<td><a name="newline-in-str-literal" id="newline-in-str-literal"></a><a href="#newline-in-str-literal-note">newline in literal</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><span style="white-space: pre-wrap;">//</span> backquote literals only:</span><br />
<span style="white-space: pre-wrap;">`</span>first line<br />
second line<span style="white-space: pre-wrap;">`</span><br />
<br />
<span style="color: gray"><span style="white-space: pre-wrap;">//</span> Backslashes can be used to break<br />
<span style="white-space: pre-wrap;">//</span> long strings.</span></td>
<td><span style="color: gray"># triple quote literals only:</span><br />
'''first line<br />
second line'''<br />
<br />
"""first line<br />
second line"""</td>
<td>'first line<br />
second line'<br />
<br />
"first line<br />
second line"</td>
<td>'first line<br />
second line'<br />
<br />
"first line<br />
second line"</td>
</tr>
<tr>
<td><a name="str-literal-esc" id="str-literal-esc"></a><a href="#str-literal-esc-note">literal escapes</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><em>single and double quotes:</em></span><br />
\b \f \n \r \t \v \x<span style="color: gray"><em>hh</em></span> \" \' \\<br />
\u<span style="color: gray"><em>hhhh</em></span> \u{<span style="color: gray"><em>hhhhh</em></span>}</td>
<td>\<span style="color: gray"><em>newline</em></span> \\ \' \" \a \b \f \n \r \t \v \<span style="color: gray"><em>ooo</em></span> \x<span style="color: gray"><em>hh</em></span> \u<span style="color: gray"><em>hhhh</em></span> \U<span style="color: gray"><em>hhhhhhhh</em></span><br />
<br />
<span style="color: gray"><em>In Python 2,</em> \u <em>and</em> \U <em>only available in string literals with</em> u <em>prefix</em></span></td>
<td><span style="color: gray"><em>double quoted:</em></span><br />
\f \n \r \t \v \x<span style="color: gray"><em>hh</em></span> \$ \" \\ \<span style="color: gray"><em>ooo</em></span><br />
<br />
<span style="color: gray"><em>single quoted:</em></span><br />
\' \\</td>
<td><span style="color: gray"><em>double quoted:</em></span><br />
\a \b \c<span style="color: gray"><em>x</em></span> \e \f \n \r \s \t \v \x<span style="color: gray"><em>hh</em></span> \<span style="color: gray"><em>ooo</em></span> \u<span style="color: gray"><em>hhhh</em></span> \u{<span style="color: gray"><em>hhhhh</em></span>}<br />
<br />
<span style="color: gray"><em>single quoted:</em></span><br />
\' \\</td>
</tr>
<tr>
<td><a name="here-doc" id="here-doc"></a><a href="#here-doc-note">here document</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><em>none</em></span></td>
<td><span style="color: gray"><em>none</em></span></td>
<td>$word = "amet";<br />
<br />
$s = <span style="white-space: pre-wrap;"><<<</span>EOF<br />
lorem ipsum<br />
dolor sit $word<br />
EOF;</td>
<td>word = "amet"<br />
<br />
s = <span style="white-space: pre-wrap;"><<</span>EOF<br />
lorem ipsum<br />
dolor sit #{word}<br />
EOF</td>
</tr>
<tr>
<td><a name="var-interpolation" id="var-interpolation"></a><a href="#var-interpolation-note">variable interpolation</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>let count = 3;<br />
let item = 'ball';<br />
let s = <span style="white-space: pre-wrap;">`</span>${count} ${item}s<span style="white-space: pre-wrap;">`</span>;</td>
<td>count = 3<br />
item = 'ball'<br />
print('{count} {item}s'.format(<br />
<span style="white-space: pre-wrap;"> </span><span style="white-space: pre-wrap;">**</span>locals()))<br />
<br />
<span style="color: gray"># Python 3.6:</span><br />
print(f'{count} {item}s')</td>
<td>$count = 3;<br />
$item = "ball";<br />
echo "$count ${item}s\n";</td>
<td>count = 3<br />
item = "ball"<br />
puts "#{count} #{item}s"</td>
</tr>
<tr>
<td><a name="expr-interpolation" id="expr-interpolation"></a><a href="#expr-interpolation-note">expression interpolation</a></td>
<td><span style="white-space: pre-wrap;">`</span>1 + 1 = ${1 + 1}<span style="white-space: pre-wrap;">`</span></td>
<td>'1 + 1 = {}'.format(1 + 1)<br />
<br />
<span style="color: gray"># Python 3.6:</span><br />
f'1 + 1 = {1 + 1}'</td>
<td><span style="color: gray"><em>none</em></span></td>
<td>"1 + 1 = #{1 + 1}"</td>
</tr>
<tr>
<td><a name="format-str" id="format-str"></a><a href="#format-str-note">format string</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td><span style="color: gray"><span style="white-space: pre-wrap;">//</span> None; use string concatenation.<br />
<span style="white-space: pre-wrap;">//</span> Evaluates to "12.35":</span><br />
12.3456.toFixed(2)</td>
<td>'lorem %s %d %f' % ('ipsum', 13, 3.7)<br />
<br />
fmt = 'lorem {0} {1} {2}'<br />
fmt.format('ipsum', 13, 3.7)</td>
<td>$fmt = "lorem %s %d %f";<br />
sprintf($fmt, "ipsum", 13, 3.7);</td>
<td>"lorem %s %d %f" % ["ipsum", 13, 3.7]</td>
</tr>
<tr>
<td><a name="mutable-str" id="mutable-str"></a><a href="#mutable-str-note">are strings mutable?</a></td>
<td><span style="color: gray"><em>no</em></span></td>
<td><span style="color: gray"><em>no</em></span></td>
<td>$s = "bar";<br />
$s2 = $s;<br />
<span style="color: gray"># sets s to "baz"; s2 is unchanged:</span><br />
$s[2] = "z";</td>
<td>s = "bar"<br />
s2 = s<br />
<span style="color: gray"># sets s and s2 to "baz":</span><br />
s[2] = "z"</td>
</tr>
<tr>
<td><a name="copy-str" id="copy-str"></a><a href="#copy-str-note">copy string</a></td>
<td><span style="color: gray"><em>none</em></span></td>
<td><span style="color: gray"><em>none</em></span></td>
<td>$s2 = $s;</td>
<td>s = "bar"<br />
s2 = s.clone<br />
<span style="color: gray"># s2 is not altered:</span><br />
s[2] = "z"</td>
</tr>
<tr>
<td><a name="str-concat" id="str-concat"></a><a href="#str-concat-note">concatenate</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>s = 'Hello, ' + 'World!';</td>
<td>s = 'Hello, '<br />
s2 = s + 'World!'<br />
<br />
<span style="color: gray"># juxtaposition can be used to<br />
# concatenate literals:</span><br />
s2 = 'Hello, ' "World!"</td>
<td>$s = "Hello, ";<br />
$s2 = $s . "World!";</td>
<td>s = "Hello, "<br />
s2 = s + "World!"<br />
<br />
<span style="color: gray"># juxtaposition can be used to<br />
# concatenate literals:</span><br />
s2 = "Hello, " 'World!'</td>
</tr>
<tr>
<td><a name="str-replicate" id="str-replicate"></a><a href="#str-replicate-note">replicate</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>let hbar = _.repeat('-', 80);</td>
<td>hbar = '-' * 80</td>
<td>$hbar = str_repeat("-", 80);</td>
<td>hbar = "-" * 80</td>
</tr>
<tr>
<td><a name="translate-case" id="translate-case"></a><a href="#translate-case-note">translate case</a><br />
<span style="color: gray"><em>to upper, to lower</em></span></td>
<td>'lorem'.toUpperCase()<br />
'LOREM'.toLowerCase()</td>
<td>'lorem'.upper()<br />
'LOREM'.lower()</td>
<td>mb_strtoupper("lorem")<br />
mb_strtolower("LOREM")<br />
<span style="color: gray"># strtoupper/strtolower are ASCII only</span></td>
<td>"lorem".upcase<br />
"LOREM".downcase</td>
</tr>
<tr>
<td><a name="capitalize" id="capitalize"></a><a href="#capitalize-note">capitalize</a><br />
<span style="color: gray"><em>string, words</em></span></td>
<td>_.capitalize('lorem');<br />
<span style="color: gray"><em>none</em></span></td>
<td>import string<br />
<br />
'lorem'.capitalize()<br />
string.capwords('lorem ipsum')</td>
<td><span style="color: gray"># ASCII only:</span><br />
ucfirst(strtolower("lorem"))<br />
ucwords(strtolower("lorem ipsum"))<br />
<span style="color: gray"># Unicode title case:</span><br />
mb_convert_case("lorem ipsum", MB_CASE_TITLE)</td>
<td>"lorem".capitalize<br />
<span style="color: gray"><em>none</em></span></td>
</tr>
<tr>
<td><a name="trim" id="trim"></a><a href="#trim-note">trim</a><br />
<span style="color: gray"><em>both sides, left, right</em></span></td>
<td>' lorem '.trim()<br />
' lorem'.trimLeft()<br />
'lorem '.trimRight()</td>
<td>' lorem '.strip()<br />
' lorem'.lstrip()<br />
'lorem '.rstrip()</td>
<td>trim(" lorem ")<br />
ltrim(" lorem")<br />
rtrim("lorem ")</td>
<td>" lorem ".strip<br />
" lorem".lstrip<br />
"lorem ".rstrip</td>
</tr>
<tr>
<td><a name="pad" id="pad"></a><a href="#pad-note">pad</a><br />
<span style="color: gray"><em>on right, on left, centered</em></span></td>
<td>_.padStart('lorem', 10)<br />
_.padEnd('lorem', 10)<br />
_.pad('lorem', 10)</td>
<td>'lorem'.ljust(10)<br />
'lorem'.rjust(10)<br />
'lorem'.center(10)</td>
<td>$s = "lorem";<br />
$delta = strlen($s) - mb_strlen($s);<br />
str_pad($s, 10 + $delta)<br />
str_pad("$s, 10 + $delta, " ", STR_PAD_LEFT)<br />
str_pad($s, 10 + $delta, " ", STR_PAD_BOTH)</td>
<td>"lorem".ljust(10)<br />
"lorem".rjust(10)<br />
"lorem".center(10)</td>
</tr>
<tr>
<td><a name="num-to-str" id="num-to-str"></a><a href="#num-to-str-note">number to string</a><br />
<span style="white-space: pre-wrap;"> </span></td>
<td>'value: ' + 8</td>
<td>'value: ' + str(8)</td>
<td>"value: " . 8</td>
<td>"value: " + 8.to_s</td>
</tr>
<tr>
<td><a name="fmt-float" id="fmt-float"></a><a href="#fmt-float-note">format float</a></td>
<td>'' + Math.round(Math.PI * 100) / 100</td>
<td>import math<br />
<br />
'%.2f' % math.pi<br />
'{:.3}'.format(math.pi)<br />
<span style="color: gray"># Python 3.6:</span><br />
f'{math.pi:.{3}}'</td>
<td>number_format(M_PI, 2)</td>
<td>include Math<br />
<br />
'%.2f' % PI<br />