bland_dan bland_dan - 1 year ago 67
jQuery Question

Comparing input fields using JQuery

I currently have an input form. There are two entries for each input class as follows:

<input type="text" name="firstname_a" class="firstname" disabled="disabled" />
<input type="text" name="firstname_b" class="firstname" />
<input type="text" name="surname_a" class="surname" disabled="disabled" />
<input type="text" name="surname_b" class="surname" />
<input type="submit" value="submit" />

On submission I want JQuery to check whether or not value a matches value b (value a has been entered by the end user, value b has been entered by a outworker working for a vetting company). The form could have upto 470 input fields, these are stored in a database dependant upon the type of vetting being carried out. I don't, therefore, want to have to type out 470 times!:

if($('input["name=firstname_a"]').val() == $('input["name=firstname_a"]').val())
// do something
// do something else

Rather I would like to find a dynamic way to do this, possibly using the serializeArray() function, but I'm struggling! All or any help would be greatly appreciated.

Answer Source

You can cycle through .each input ending in _a and do the comparison with its _b counterpart:

$('#target').submit( function() {

    // Iterate over each input with name ending in _a
    $('input[name$="_a"]').each( function() {

        // Get the base name by removing _a
        var name = $(this).attr('name').replace(/_a$/, '');

        // Compare _a to _b
        if( $('input[name="'+name+'_a"]').val() != $('input[name="'+name+'_b"]').val()) {
             alert(name+" field does not match!");   

    return false;


Here is a version where all mismatches are saved and alerted at the end:

Or a version that highlights the errors:

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