jQuery单选按钮检查问题

Question

I'm using Jquery to store the value of a checked set of radio buttons into a variable and it works fine, but the issue I'm having is when someone decides to skip the question (skip the set of radio buttons -ie don't select an option) the value that is returned in the variable is 'undefined'. I would like to have the value returned as blank (no value) if someone decides to skip a set of radio buttons. Is there an easy method to do this in Jquery?

Jquery:

`var raq1= $('input[type=radio][name=q1]:checked').val();`

HTML:

`<input type="radio"  name="q1" id="qn1i5" value="5">
 <input type="radio"  name="q1" id="qn1i4" value="4">
 <input type="radio"  name="q1" id="qn1i3" value="3">
 <input type="radio" name="q1" id="qn1i2" value="2">
 <input type="radio" name="q1" id="qn1i1" value="1">`

Answer 1

What you want to do is check whether $('input[type=radio][name=q1]:checked').val() exists. If it exists, set that value to raq1 . If it doesn't, you simply set raq1 to be an empty string.

This can be done with the following ternary :

$('input[type=radio][name=q1]:checked').val() ? $('input[type=radio][name=q1]:checked').val() : ''

And can be seen in the following:

 document.getElementsByTagName('button')[0].addEventListener("click", function() { var raq1 = $('input[type=radio][name=q1]:checked').val() ? $('input[type=radio][name=q1]:checked').val() : ''; console.log(raq1); }); 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <input type="radio" name="q1" id="qn1i5" value="5"> <input type="radio" name="q1" id="qn1i4" value="4"> <input type="radio" name="q1" id="qn1i3" value="3"> <input type="radio" name="q1" id="qn1i2" value="2"> <input type="radio" name="q1" id="qn1i1" value="1"> <button>Get Values</button> 

Hope this helps!