feat: markdown documentation

Author: claudioaltamura

README.md

@@ -8,4 +8,5 @@ Java 25 features examples
 - ScopedValue
 - instance main method
 - module import declarations
-- flexible constructor bodies
+- flexible constructor bodies
+- markdown documentation

src/main/java/de/claudioaltamura/java25/markdowndocumentation/CharReplacer.java

@@ -0,0 +1,35 @@
+package de.claudioaltamura.java25.markdowndocumentation;
+
+public class CharReplacer {
+
+    public String replace(String input) {
+        if (input == null) {
+            throw new IllegalArgumentException("Input string cannot be null");
+        }
+
+        var ret = replace(input, "e", "3");
+        ret = replace(ret, "o", "0");
+
+        return ret;
+    }
+
+    /// Replaces all occurrences of the target string with the replacement string in the input string.
+    ///
+    /// @param input the string to perform the replacement on
+    /// @param target the string to be replaced
+    /// @param replacement the string to replace the target with
+    /// @return a new string with the replacements made
+    /// @throws IllegalArgumentException if input is null, target is null or empty, or replacement is null
+    String replace(String input, String target, String replacement) {
+        if (input == null) {
+            throw new IllegalArgumentException("Input string cannot be null");
+        }
+        if (target == null || target.isEmpty()) {
+            throw new IllegalArgumentException("Target string cannot be null or empty");
+        }
+        if (replacement == null) {
+            throw new IllegalArgumentException("Replacement string cannot be null");
+        }
+        return input.replace(target, replacement);
+    }
+}

src/test/java/de/claudioaltamura/java25/markdowndocumentation/CharReplacerTest.java

@@ -0,0 +1,24 @@
+package de.claudioaltamura.java25.markdowndocumentation;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class CharReplacerTest {
+
+    @Test
+    void replaceAll() {
+        CharReplacer charReplacer = new CharReplacer();
+        String result = charReplacer.replace("Hello World!");
+        assertEquals("H3ll0 W0rld!", result);
+    }
+
+
+    @Test
+    void replace() {
+        CharReplacer charReplacer = new CharReplacer();
+        String result = charReplacer.replace("Hello World!", "o", "0");
+        assertEquals("Hellx Wxrld!", result);
+    }
+
+}