CODEWITHSUNDEEP
jquery
Alex
Alex

Reputation: 6665

Checking for blank input with jQuery

I'm submitting some comments via $.ajax. However I want to check to make sure that some content is entered in the input box. At the moment I am using this:

if ($("#comments").val().length != 0){

However this only works if a user leaves in the input blank, if the leave a space or return then it will pass. How can I improve this if?

Upvotes: 14

Views: 18402

Answers (4)

Juan Gonzales
Juan Gonzales

Reputation: 1977

I know this is an incredibly late answer, but I am using this...

var self = $(this).val(); 
if (!self || self[0] == ' '){
  //////do something
}

and it works well! hope someone else can get some use out of it!

Upvotes: 1

Vikrant Chaudhary
Vikrant Chaudhary

Reputation: 11319

In JavaScript

//Following all return true
"" == false
" " == false
"  " == false
"   " == false
//Not related to question but interesting
//Following all (also) return true
!" " == false
!"  " == false
!"   " == false
//Except
!"" == false //returns false

(Verified with Firebug console and Chromium's Developer Tools console).

Upvotes: 2

Dominic Rodger
Dominic Rodger

Reputation: 99841

Remove whitespace before checking for empty:

if ($("#comments").val().replace(/^\s+|\s+$/g, "").length != 0){

Upvotes: 22

user57508
user57508

Reputation:

you might go for a trim-function ... google give us some nice links. btw ... jQuery does have a trim-function

eg.

var trimmedValue = jQuery.trim($('#comments').val());
if (trimmedValue.length > 0) {
   // TODO
}

Upvotes: 19

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