如何使用jQuery检查元素是否包含类（） _CSS元素

方法1：使用hasClass()方法:hasClass()是jQuery中的内置方法, 用于检查具有指定类名的元素是否存在。它返回一个布尔值, 指定该类是否存在于元素中。这可用于检查多个类。
【如何使用jQuery检查元素是否包含类（）】语法如下：

$('element').hasClass('className')

例子：

< !DOCTYPE html> < html> < head> < title> How to check an element contains a class using jQuery? < /title> < script src = "https://code.jquery.com/jquery-3.3.1.min.js"> < /script> < /head> < body> < h1 style = "color: green"> lsbin < /h1> < b> How to check an element contains a class using jQuery? < /b> < p class = "example-class"> This element has "example-class". < /p> < p> Does the element have class? < span class = "output"> < /span> < /p> < button onclick = "checkForClass()"> Click to check < /button> < !-- Script to use hasClass() method to check the existence of class name --> < script type = "text/javascript"> function checkForClass() { classCheck = $('p').is('.example-class'); document.querySelector('.output').textContent = classCheck; } < /script> < /body> < /html>

输出如下：

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方法2：使用is()方法:这类似于以上方法, 并且可以根据需要用于检查更多属性。选择必需元素, 然后像CSS类选择器一样传递类名。它返回一个布尔值, 指定该类是否存在于元素中。这可用于检查多个类。
语法如下：

$('element').is('.className')

例子：

< !DOCTYPE html> < html> < head> < title> How to check an element contains a class using jQuery? < /title> < script src = "https://code.jquery.com/jquery-3.3.1.min.js"> < /script> < /head> < body> < h1 style = "color: green"> lsbin < /h1> < b> How to check an element contains a class using jQuery? < /b> < p class = "example-class"> This element has "example-class". < /p> < p> Does the element have class? < span class = "output"> < /span> < /p> < button onclick = "checkForClass()"> Click to check < /button> < !-- Script to use is() method to check the existence of class name --> < script type = "text/javascript"> function checkForClass() { classCheck = $('p').is('.example-class'); document.querySelector('.output').textContent = classCheck; } < /script> < /body> < /html>

输出如下：