Deep freeze object
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