Question

37

rated 0 times [ 39] [ 2] / answers: 1 / hits: 36511 / 6 Years ago, fri, july 20, 2018, 12:00:00

When I want to copy the state like this:

let copy = this.state.foo

copy.push('bar')

the state copied correctly, but with its reference, and when I change 'copy' the main state changes.

What should I do to avoid this change?

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Location: Saint Helena

Member since Tue, Nov 3, 2020

4 Years ago

answered 6 Years ago harleyaleenag · Accepted Answer

You can use array spread or Array.concat() to make a shallow clone, and add new items as well):

const state = {

  foo: ['bar']

};



const copy = [...state.foo, 'bar'];



console.log(copy === state.foo); // false