难以理解JSX传播算子 [英] Trouble understanding JSX spread operator
问题描述
从React文档中获得以下示例代码:
Given this example code from the React docs:
var props = {};
props.foo = x;
props.bar = y;
var component = <Component {...props} />;
我仔细研究了...props
的实际计算结果,这是这样的:
I did some looking into what ...props
actually evaluates to, which is this:
React.__spread({}, props)
反过来求值为{foo: x, bar: y}
.
但是我想知道的是,为什么我不能这样做:
But what I'm wondering is, why can't I just do this:
var component = <Component props />;
我看不出点差运算符的含义是什么.
I don't see understand what the point of the spread operator is.
推荐答案
这有助于使代码更简洁-由于props
是对象,所以散布运算符采用您所对象的 properties 传入并将它们应用于组件.因此,该组件将具有值为x
的foo
和值为y
的bar
属性.
This helps make your code more succinct - since props
is an object, the spread operator takes the properties of the object you pass in and applied them to the component. So the Component will have properties a foo
with a value of x
and a bar
with a value of y
.
它与以下内容相同:
var component = <Component foo={props.foo} bar={props.bar} />;
短些
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