jQuery中的属性选择器中的美元符号是什么意思? [英] What does the dollar sign mean inside an attribute selector in jQuery?
问题描述
有一个jQuery似乎用id="scuba"查找所有元素，但是随后它使用attr()来提取id? "scuba"是否可以作为ID的一部分，而attr会将整个ID抽出?我从未见过$属性选择器内部，就像下面的示例一样.
There is this jQuery which seems to look for all elements with id="scuba", but then it uses attr() to pull the id out? Could "scuba" be part of the id and attr pulls the entire id out? I've never seen the $ inside an attribute selector, just outside like the example below.
$('*[id$=scuba]').attr('id')
所以我的问题是:
- 在此示例中
$或$=的作用 - 这段代码有什么作用?
- What does the
$or$=do in this example - What does this code do?
推荐答案
美元符号
第一个$是jQuery()函数( jQuery对象构造函数)的简写.
The first $ is a shorthand for the jQuery() function, the jQuery object constructor.
换句话说，这是一个名为$的变量，已被分配一个名为jQuery的函数，如在jQuery源的最小版本中所示:window.jQuery = window.$ = jQuery;
In other words, it's a variable called $ that's been assigned a function called jQuery, as can been seen in the unminified version of the jQuery source: window.jQuery = window.$ = jQuery;
美元等于符号
第二个$是名为属性以选择器结尾的jQuery选择器的一部分.在属性选择器中使用时，$=是逻辑运算符，其字面意思是如果左侧值以右侧值结尾，则为 true ".
The second $ is part of a jQuery selector called Attribute Ends With Selector . When used in an attribute selector, $= is a logical operator that literally means "true if the left-hand value ends with the right-hand value".
此脚本的实际作用
总体而言，此代码段首先选择以scuba结尾的具有id属性的任何元素.然后，它从生成的jQuery对象中检索第一个元素的id值.
Overall, this snippet first selects any element with an id attribute ending in scuba. It then retrieves the id value of the first element from the resulting jQuery object.
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