在 setState() 中使用 Math.pow() 方法

Question

In my example of reactjs code the method Math.pow() must change the value of div element on every click of button, but the method doesn't work, explain me, please, why.

handlerButton=(e)=> {           
   this.setState(function(prevState) {
   return({number: Math.pow(prevState.number, 2)});     
    }); 
}   

Answer 1

Change:

<MyButton handlerButton={this.handlerButton}/>

to :

<MyButton onClick={this.handlerButton}/>

Answer 2

<MyButton handlerButton={this.handlerButton}/>

You're passing in a prop named handlerButton , but you never use props.handlerButton inside MyButton. Instead, you're using props.onClick

render() { 
    return <button id="btn" className="mybutton" onClick={this.props.onClick}>pow</button>;  
}

You need to use the same prop name in both places.