do something if element hidden [duplicate]

Question

how can i check a if an element is visible or hidden with jquery and perform some action?

below given is my form related code,

<form>
First name: <input type="text" name="firstname"><br>
Last name: <input type="text" name="lastname"><br>
Full name: <input type="text" name="fullname"><br>
DOB: <input type="text" name="dob">
Address: <input type="text" name="address">
</form>

i need to hide the full name text field when first name text field or last name text field is displaying.

Answer 1

try something like this

if($('#testElement').is(':visible')){
   //what you want to do when is visible
}

for your code

if($('input[name="firstname"], input[name="lastname"]').is(':visible')){
  $('input[name="fullname"]').hide();
}

REFERENCE

http://api.jquery.com/visible-selector/

Answer 2

if($('input[name="firstname"], input[name="lastname"]').is(':visible') === true)
    $('input[name="fullname"]').hide();