Regarding Jquery validation - php

Question

I put the jquery validation on select filed and i take field name is name="course[]". I take it in array because I want to store multiple selected option in table but when i use this name in validation that time my validation is not working on select field can anyone suggest me any solution.
My jquery code is here:-
<script type="text/javascript">
$("#formValidate").validate({
rules: {
course:{
required: true
},
messages: {
course:{
required: "Enter a username";
},
errorElement : 'div',
errorPlacement: function(error, element) {
var placement = $(element).data('error');
if (placement) {
$(placement).append(error)
} else {
error.insertAfter(element);
}
}
});
</script>
my html field code is here:-
<form class="formValidate" id="formValidate" action="" method="POST">
<select multiple id="course" name="course[]">
<option value="Php">PHP</option>
<option value="ruby">RUBY</option>
<option value="wordpress">WORDPRESS</option>
<option value="java">java</option>
</select>
</form>

Answer 1

The issue is that your field name is course[], not course. Therefore you need to wrap the object key in quotes and include the braces.
Also note that your code has some errors; you've placed a ; within an object which is a syntax error, and you're missing a closing }.
$("#formValidate").validate({
rules: {
'course[]': { // note the quotes and braces here
required: true
},
messages: {
course: {
required: "Enter a username"
},
errorElement: 'div',
errorPlacement: function(error, element) {
var placement = $(element).data('error');
if (placement) {
$(placement).append(error)
} else {
error.insertAfter(element);
}
}
}
}
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.17.0/jquery.validate.min.js"></script>
<form class="formValidate" id="formValidate" action="" method="POST">
<select multiple id="course" name="course[]">
<option value="Php">PHP</option>
<option value="ruby">RUBY</option>
<option value="wordpress">WORDPRESS</option>
<option value="java">java</option>
</select>
<button>Submit</button>
</form>

Answer 2

If you use array add field name with [] along with ' or "
("#formValidate").validate({
rules: {
"course[]":{
required: true
},
messages: {
"course[]":{
required: "Enter a username";
},
errorElement : 'div',
errorPlacement: function(error, element) {
var placement = $(element).data('error');
if (placement) {
$(placement).append(error)
} else {
error.insertAfter(element);
}
}
});
</script>

Answer 3

See my updated code below, it will print validation message 'Enter a username' which not showing on other user's answers as they missed a closing } in rules in their code.
$("#formValidate").validate({
rules: {
'course[]': { required: true }
},
messages: {
'course[]': { required: 'Enter a username' },
errorElement: 'div',
errorPlacement: function(error, element) {
var placement = $(element).data('error');
if (placement) {
$(placement).append(error);
} else {
error.insertAfter(element);
}
}
}
});