如何根据 Jquery 中的值向子 div 动态添加和删除 class

Question

if data value is matching with any div inside requestsampler class then dynamically add new class(sampleClass) to test class inside the matching container

js:

var data = **somevalue**;

data is dynamic value

html:

<div class="requestsampler">
  <div class= "**somevalue**">
    <div class="test">  // add new class <div class="test sample class">
     //
    </div>
    
  </div>
   <div class= "somevalue2">
     <div class="test">
      //
    </div>
    
  </div>
   <div class= "somevalue3">
     <div class="test">
      //
    </div>
    
  </div>
</div>

tried not working:

$('.requestsampler').hasClass(data) {
  $(.'requestsampler .`${data}` .test').addClass('sampleclass');
}

Answer 1

You could simply use Attribute Contains Prefix Selector [name|="value"] for more info please refer http://jqapi.com/#p=attribute-contains-prefix-selector. . below is the code for your example.

 $(document).ready(()=>{ var data = "somevalue"; $('div[class|="'+data+'"]>.test').addClass("sampleclass"); })

 .sampleclass{ background-color:red; }

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <div class="requestsampler"> <div class= "somevalue"> <div class="test"> // add new class <div class="test sample class"> // </div> </div> <div class= "somevalue2"> <div class="test"> // </div> </div> <div class= "somevalue3"> <div class="test"> // </div> </div> </div>

Answer 2

you could try jquery elem.find() api. And also use className with string and numeric combination instead of symbols

i have changed the condition with element find length. Because hasClass() only perform on the selector element. So if you are using find() they will find the matched element.

And also your if condition does not make any sense, without condition is also working same

Updated

If you need first test element. use .eq(0) or else use different className for the first test element

 var data = "somevalue"; if ($('.requestsampler').find(`.${data}`).length > 0) { $('.requestsampler').find(`.${data}`).find('.test').eq(0).addClass('sampleclass'); }

 .sampleclass { background: red; }

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <div class="requestsampler"> <div class="somevalue"> <div class="test"> // add new class <div class="test sample class"> sample </div> </div> <div class="somevalue2"> <div class="test"> // </div> </div> <div class="somevalue3"> <div class="test"> // </div> </div> </div>