Jquery Form validation for select2 multiple [duplicate]

Question

I have form in which I have field courses with multi select option. Also there are more than 2courses field in form like below :-

1. name="courses[0][]"
2. name="courses[1][]"

How can I validate below :-

rules: {
 "courses[][]":{
   required:true
 }
}

Answer 1

What you're trying to do will not work. You can use jQuery.validator.addClassRules instead.

• Add a class like courses to the fields you want to validate.
• Add the rules for the fields (from step 1) using jQuery.validator.addClassRules before you initialize jquery validate.

Try something like this

$(document).ready(function(){
    $.validator.messages.required = 'File name mandatory!';
    $.validator.addClassRules('fileName', {
        required: true
    });

    $("form").validate();
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="http://ajax.aspnetcdn.com/ajax/jquery.validate/1.8/jquery.validate.min.js"></script>
<form action="#">
    <input type="text" id="name1" class="fileName" name="name1"/><br>
    <input type="text" id="name2" class="fileName" name="name2"/><br>
    <input type="text" id="name3" class="fileName" name="name3"/><br>
    <input type="text" id="name4" class="fileName" name="name4"/><br>
    <input type="submit" />
</form>