diff --git a/javascript/LeetCode/Array/645.js b/javascript/LeetCode/Array/645.js
new file mode 100644
index 0000000..8760316
--- /dev/null
+++ b/javascript/LeetCode/Array/645.js
@@ -0,0 +1,33 @@
+/**
+ * 645. Set Mismatch
+ * 
+ * 參數為數字陣列，從1至n，但內有重複的元素，找出重複的元素並調整成對的元素，變成1至N且無重複的元素
+ *
+ * @param {number[]} nums
+ * @return {number[]}
+ */
+var findErrorNums = function(nums) {
+  // TC:O(N)
+  let map = new Map();
+  let duplicate = 0, missing = 0;
+  for(let i = 1;i <= nums.length;++i){   
+    map.set(i,0);
+  }
+  // 增加或減少
+  for(const ele of nums){
+    map.set(ele,map.get(ele) - 1);
+  }
+  // console.log(map)
+  for(const [key,value] of map) {
+    if(value === -2){
+      duplicate = key
+    }
+    if(value === 0){
+      missing = key;
+    }
+  }
+  return [duplicate,missing];
+};
+let nums = [1,2,2,4];
+// [2,3]
+console.log(findErrorNums(nums));
\ No newline at end of file
diff --git a/javascript/index.js b/javascript/index.js
index ab38037..990dd88 100644
--- a/javascript/index.js
+++ b/javascript/index.js
@@ -1385,32 +1385,6 @@ Query 2: The element at queries[2] = 5 is nums[5] = 3. The nearest index with th
 */
 // console.log(solveQueries(nums,queries));
 
-/**
- * 645. Set Mismatch
- * 
- * 參數為數字陣列，從1至n，但內有重複的元素，找出它們並調整成對的元素
- *
- * @param {number[]} nums
- * @return {number[]}
- */
-var findErrorNums = function(nums) {
-  let res = [];
-  let map = new Map();
-  for(const ele of nums){
-    map.has(ele) ? map.set(ele,map.get(ele) + 1 ) : map.set(ele,1);
-  }
-  // console.log(map)
-  for(const [key,value] of map) {
-    if(value >= 2){
-      console.log(key);
-
-    }
-  }
-};
-let nums = [1,2,2,4];
-// [2,3]
-// console.log(findErrorNums(nums));
-
 
 /**
  * 2864. Maximum Odd Binary Number
@@ -1429,4 +1403,4 @@ var maximumOddBinaryNumber = function(s) {
 let s = "010";
 // Output: "001"
 // Explanation: Because there is just one '1', it must be in the last position. So the answer is "001".
-console.log(maximumOddBinaryNumber(s));
\ No newline at end of file
+// console.log(maximumOddBinaryNumber(s));
\ No newline at end of file