<select>要求不起作用

I'am using this code along with php code for a select and used required class to make it mandatory but it is not working. Does anyone can help me.I have included this html section along with php code.

 <select name="category" required="required" class="form-control">
        <option value=" ">--Select Category--</option>
        <option value="asd">asd</option>
    </select>

Try to remove space value in your select category option

<select name="category" required="required" class="form-control">
    <option value="">--Select Category--</option>
    <option value="asd">asd</option>
</select> code here

First of all, replace

 <option value=" ">--Select Category--</option>

with

 <option value="">--Select Category--</option>

And then, as w3c says, ... "The required attribute is a boolean attribute. When specified, the element is required."

 <select name="category" required class="form-control">
     <option value="">--Select Category--</option>
     <option value="asd">asd</option>
 </select>

Also here you can find same example.

And here you can try the code.

Required is working. The fact is that " " is a value and "" is not.

Try changing the required part to true

So it'll be like required="true", did it work?

You are using required only which is HTML5 validation, may be its not work on all browser. Is you are looking for the proper validation i suggest to with jquery validation. Validation Document