How can I insert into React's state array with setState?
Clone the current state using slice()
. By doing this, the original state remains unaffected till setState()
. After cloning, do your operations over the cloned array and set it in the state. The previous answer will mutate the state. Read about this here
let a = this.state.arr.slice(); //creates the clone of the statea[index] = "random element";this.setState({arr: a});
use spread operator https://codeburst.io/javascript-es6-the-spread-syntax-f5c35525f754
let newChild = "newChild"this.setState({ children: [ ...this.state.children, newChild ]})
UPDATE
Just use Object.assign() as suggested here to make a copy of your state.
Thus, you can do it as follows :
let new_state = Object.assign({}, this.state); let a = new_state.arr;a[index] = "random element";this.setState({arr: a});
Hope it helps.