On state change of one component re-render second component

Question

Component A
this.state = {
    x: 1,
    y: 2
}

reset () {
    this.setState ({
        x: 3,
        y: 5
    })
}


render () {
    

        

Answer 1

You need to setState for the second component too in the componentWillReceiveProps function. Constructor is only called on intial render and state should not be only assigned in the contructor if it depends on props

componentWillReceiveProps (nextProps) {

    this.setState({z: nextProps.x + nextProps.y})
}

if you want to use someMethod do it like

someMethod(props) {
     props? return props.x + props.y : return this.props.x + this.props.y
}

and then in componentWillReceiveProps

 componentWillReceiveProps (nextProps) {
    var z = someMethod(nextProps)
    this.setState({z})
}