added problem number 18

Author: mehediislamripon

Diff for: README.md

@@ -19,4 +19,5 @@
 | Problem - 15  | Get the Middle Character  |
 | Problem - 16  | Generate  random boolean in JavaScript  |
 | Problem - 17  | Find the largest number in Javascript  |
+| Problem - 18  | Copy an Object deeply  |
 <!-- | Problem - 18  |   | -->

Diff for: problem-18.js

@@ -0,0 +1,13 @@
+// JavaScript allows you to deep copy an object by converting it into string and then back into object.
+
+let obj = {
+   name: 'mehedi',
+   address: 'dinajpur',
+   mail: '[email protected]',
+};
+
+const deepCopy = (obj) => {
+   return JSON.parse(JSON.stringify(obj));
+};
+
+console.log(deepCopy(obj));