在React JSX中的循环内循环

Question

I am trying to render in react, jsx, a loop inside of a loop Like bellow:

{this.state.ans.map(function(item) {
    return (
        {this.state.quest.map(
            function(item1) {return (item1)}
        )}        
        {item}
    )
})}

This does not work any other suggestions

Answer 1

You forgot the wrapping div in your first map statement:

render() {
  return (
    <div>
      {this.state.ans.map(item =>
        <div> // this div was missing
          {this.state.quest.map(quest => quest)}
          {item}
        </div>
      )}
    </div>
  )
}

Answer 2

Try it like this:

render(){
    return (
        .
        .
        .
        {this.state.ans.map((item) => {
            return (
                <div>
                    {this.state.quest.map((item1) => { 
                           return (item1); 
                        }
                    )}        
                   {item}
               </div>
            );
        })}
    );
}

Basically the idea is that, you should return a single element - in my example a div (with the latest react version you don't have to). And moreover, use lambdas in order for this to reference the correct context.

If you do not use ES6, you can add the following statement at the beginning of the render method:

var that = this;

and use that afterwards with the function(){} syntax inside the return .