What is the best way to add a value to an array in state
I have an array in state, let's say this.state.arr. I want to add something to this state property, and then change some more properties. Option 1 onChange(event){ this.state.arr.push('newvalue'); ... this.setState({some:'val',arr:this.state.arr}) } Option 2 onChange(event){ var newArr = this.state.arr; ... newArr.push('newvalue'); ... this.setState({some:'val',arr:newArr}) } So.. I know this.state is supposed to be treated immutable. But is it ok to use it like in option 1 where I still set the state from it, or do I need to go with something like option 2, and thus always first making a copy