Deep freeze object
JavaScript, Object, Recursion · Oct 19, 2020
Deep freezes an object.
- Use
Object.keys()to get all the properties of the passed object,Array.prototype.forEach()to iterate over them. - Call
Object.freeze()recursively on all properties, applyingdeepFreeze()as necessary. - Finally, use
Object.freeze()to freeze the given object.
const deepFreeze = obj => {
Object.keys(obj).forEach(prop => {
if (typeof obj[prop] === 'object') deepFreeze(obj[prop]);
});
return Object.freeze(obj);
};'use strict';
const val = deepFreeze([1, [2, 3]]);
val[0] = 3; // not allowed
val[1][0] = 4; // not allowed as well
