为什么val（）在列表上工作但属性不起作用？(Why val() work on a list but an attribute does not?)

为什么val（）在列表上工作但属性不起作用？(Why val() work on a list but an attribute does not?)

这是我的咖啡

name = @$ '#require-name' console.log name.val()

显然， name是一个元素列表。 但是， val()可以正确返回列表中唯一元素所持有的值。

但是如果我想获得这个元素的属性的值，我会得到undefined 。 为什么是这样？

在代码的其他部分，我想单独引用这个元素#require-name 。 所以我写这个

name = @$('#require-name')[0]

它对我来说并不是很优雅。 我想取消索引（ [0] ），因为只有这一个元素。 有没有更好的方式表达这个？

This is my coffeescript

name = @$ '#require-name' console.log name.val()

Apparently name is a list of element. However the val() can correctly return the value held by the only element in the list.

But if I want to get the value of an attribute of this element, I get undefined. Why is this?

In other part of the code I want to refer to this element #require-name alone. So I write this as

name = @$('#require-name')[0]

It does not feel very elegant to me. I want to do away the indexing ([0]) since there will only be this one element. Is there a better way to express this?

最满意答案

$('#require-name')返回jQuery对象，因此.val()用于获取值。 @$('#require-name')[0]返回基础DOM元素，因此您可以访问name.checked等name.checked

或者，您可以使用.prop()方法

$('#require-name').prop('checked')

$('#require-name') returns you jQuery object thus .val() is used for fetching the values. Where as @$('#require-name')[0] return you underlying DOM element thus you can access properties like name.checked

Or, You can use .prop() method

$('#require-name').prop('checked')