我如何使用带有响应的循环? [英] How do i use for loops with react?

问题描述

我是一个非常新的响应者，我真正想要的是一个简单的for循环，该循环为我数组中的每个用户创建menuitem元素，其标题是他们的名字.所以这就是我要写的方式，但是我不知道如何做出反应.我认为应该在地图上，但我似乎无法使它正常工作，希望这里的任何人都可以帮助我.

I'm very new to react and all I really want is a simple for loop that creates menuitem elements for each user in my array with the title of it being their firstname. So this is how I would write it, but I have no clue of how to do this in react. I think it should be with a map maybe but I cant seem to get it to work either hopefully anyone out here can help me.

for (var i = 0; i < Users.length; i++) {
  <MenuItem eventKey=[i]>User.firstname[i]</MenuItem>
}

推荐答案

组件的render方法或无状态组件函数将返回要渲染的元素.

The render method of your component, or your stateless component function, returns the elements to be rendered.

如果要使用循环，可以:

If you want to use a loop, that's fine:

render() {
    let menuItems = [];
    for (var i = 0; i < Users.length; i++) {
        menuItems.push(<MenuItem eventKey=[i]>User.firstname[i]</MenuItem>);
    }
    return <div>{menuItems}</div>;
}

更常见的是看到一种更实用的样式，例如使用地图返回元素数组:

More common would be to see a more functional style, such as using a map to return the array of elements:

render() {
    return <div>
    {
        Users.map((user, i) =>
            <MenuItem eventKey=[i]>User.firstname[i]</MenuItem>)
    }
    </div>;
}

请注意，在任何一种情况下，数组的每个元素都缺少key属性，因此您将看到警告.数组中的每个元素都应具有唯一键，最好是某种形式的ID，而不仅仅是数组索引.

Note that in either case, you are missing the key property from each element of your array, so you will see warnings. Each element in an array should have a unique key, preferably some form of ID rather than just the array index.

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