implementing vanilla array_difference function

main.js

@@ -88,3 +88,21 @@ function microtime() {
 
     return now;
 }
+
+// accepting single level array with "value" as key
+function array_difference(firstArray, secondArray) {
+    var cloneArray = [];
+    
+    // create hardcopy
+    for (var i = 0; i < firstArray.length; i++) {
+        cloneArray.push(firstArray[i]);
+    }
+    
+    for (var i = 0; i < secondArray.length; i++) {
+        if (cloneArray.indexOf(secondArray[i]) != -1) {
+            cloneArray.splice(cloneArray.indexOf(secondArray[i]), 1);
+        }
+    }
+    
+    return cloneArray;
+}