从对象数组渲染 React 组件 [英] Rendering React Components from Array of Objects

问题描述

我有一些叫做站的数据，它是一个包含对象的数组.

站:[{呼叫:'第一站'，频率:'000'}，{呼叫:'第二站'，频率:'001'}]

我想为每个数组位置渲染一个 ui 组件.到目前为止我可以写

 varstationsArr = []for (var i = 0; i < this.data.stations.length; i++) {车站Arr.push(<div className="站">{this.data}

)}

然后渲染

render(){返回 ({stationsArr})}

问题是我正在打印所有数据.我只想显示一个像 {this.data.call} 这样的键，但它什么也不打印.

如何遍历这些数据并为数组的每个位置返回一个新的 UI 元素?

解决方案

您可以将站点列表映射到 ReactElements.

使用 React >= 16，可以从同一个组件返回多个元素，而无需额外的 html 元素包装器.从 16.2 开始，有一个 新语法 <> 创建片段.如果这不起作用或您的 IDE 不支持，您可以使用 代替.在 16.0 和 16.2 之间，您可以对片段使用非常简单的polyfill.

试试下面的方法

//现代语法 >= React 16.2.0const 测试 = ({站}) =>(<>{stations.map(station => (<div key={station.call} className='station'>{station.call}</div>))}</>);//现代语法 <反应 16.2.0//你需要在这里包装一个额外的元素，比如 divconst 测试 = ({站}) =>(<div>{stations.map(station => (<div className="车站"key={station.call}>{station.call}

))}

);//旧语法var 测试 = React.createClass({渲染:函数(){var stationComponents = this.props.stations.map(function(station) {return

{station.call}

;});返回 <div>{stationComponents}</div>;}});var 站 = [{呼叫:'第一站'，频率:'000'}，{呼叫:'第二站'，频率:'001'}];ReactDOM.render(<div><测试站={站}/>

,document.getElementById('容器'));

不要忘记 key 属性！

https://jsfiddle.net/69z2wepo/14377/

I have some data called stations which is an array containing objects.

stations : [
  {call:'station one',frequency:'000'},
  {call:'station two',frequency:'001'}
]

I'd like to render a ui component for each array position. So far I can write

 var stationsArr = []
 for (var i = 0; i < this.data.stations.length; i++) {
     stationsArr.push(
         <div className="station">
             {this.data}
         </div>
     )
 }

And then render

render(){
 return (
   {stationsArr}
 )
}

The problem is I'm getting all of the data printing out. I instead want to just show a key like {this.data.call} but that prints nothing.

How can I loop through this data and return a new UI element for each position of the array?

解决方案

You can map the list of stations to ReactElements.

With React >= 16, it is possible to return multiple elements from the same component without needing an extra html element wrapper. Since 16.2, there is a new syntax <> to create fragments. If this does not work or is not supported by your IDE, you can use <React.Fragment> instead. Between 16.0 and 16.2, you can use a very simple polyfill for fragments.

Try the following

// Modern syntax >= React 16.2.0
const Test = ({stations}) => (
  <>
    {stations.map(station => (
      <div key={station.call} className='station'>{station.call}</div>
    ))}
  </>
); 

// Modern syntax < React 16.2.0
// You need to wrap in an extra element like div here

const Test = ({stations}) => (
  <div>
    {stations.map(station => (
      <div className="station" key={station.call}>{station.call}</div>
    ))}
  </div>
); 

// old syntax
var Test = React.createClass({
    render: function() {
        var stationComponents = this.props.stations.map(function(station) {
            return <div className="station" key={station.call}>{station.call}</div>;
        });
        return <div>{stationComponents}</div>;
    }
});
 
var stations = [
  {call:'station one',frequency:'000'},
  {call:'station two',frequency:'001'}
]; 

ReactDOM.render(
  <div>
    <Test stations={stations} />
  </div>,
  document.getElementById('container')
);

Don't forget the key attribute!

https://jsfiddle.net/69z2wepo/14377/

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