Create 1323-maximum-69-number.js

javascript/1323-maximum-69-number.js

@@ -0,0 +1,21 @@
+/**
+ * @param {number} num
+ * @return {number}
+ */
+var maximum69Number = function (num) {
+    let maxArr = [num]; // initialize array maxArr with num as value
+
+    let numArr = num.toString().split(''); // initialize numArr as array of num
+
+    for (let i = 0; i < numArr.length; i++) { // loop through the every element of array numArr
+
+        if (numArr[i] == 6) { // if current element of numArr is 6
+            let arr = [...numArr] // copy numArr into arr
+            arr.splice(i, 1, 9); // make current element arr to 9
+            maxArr.push(arr.join('')); // convert arr to string and push into maxArr and break the loop
+            break;
+        }
+    }
+
+    return Math.max(...maxArr); // return max value from maxArr
+};