---
title: Prevent Object Mutation
---
 Remember to use **`Read-Search-Ask`** if you get stuck. Try to pair program  and write your own code 
### Problem Explanation:
We need to prevent `MATH_CONSTANTS` value from changing.
##  Hint: 1
* Use Object.freeze(obj) to prevent object from being changed.
> _try to solve the problem now_
## Spoiler Alert!
**Solution ahead!**
##  Basic Code Solution:
```javascript
function freezeObj() {
"use strict";
const MATH_CONSTANTS = {
PI: 3.14
};
Object.freeze(MATH_CONSTANTS);
try {
MATH_CONSTANTS.PI = 99;
} catch( ex ) {
console.log(ex);
}
return MATH_CONSTANTS.PI;
}
const PI = freezeObj();
```
 Run Code
# Code Explanation:
By using Object.freeze() on `MATH_CONSTANTS` we can avoid manipulating it.
#### Relevant Links
* Object.freeze()
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