CODEWITHSUNDEEP
javascriptjqueryif-statement
Chris22
Chris22

Reputation: 2043

is this correct syntax in jquery/javascript?

In the jquery below should there be a closing paretheses ")" before the "dot" in:

".test($ ..."?

(/^\s*$/.test($(this).val()))

$(document).ready(function () {
    $('#userlogin').css('color', '#cccccc').val('LOGINNAME');   

    $('#userlogin').blur(function () {
        if (/^\s*$/.test($(this).val())) {
            $(this).val('LOGINNAME');
            $(this).css('color', '#cccccc');
            $(this).valid();
        }
    }).focus(function () {
        if ($(this).val() === 'LOGINNAME') {
            $(this).val('');
            $(this).css('color', '#000000');
        }
    });

If not, why not? That code looks a little weird to me.

Upvotes: 2

Views: 99

Answers (4)

Sampson
Sampson

Reputation: 268512

/^\s*$/.test( $(this).val() )

The first part is a regular expression - not a string or anything else. As such, it begins and ends with deliminters / and /.

Using .match is sometimes more legible as it doesn't appear to have some strange unbound item floating around in the source:

$(this).val().match(/^\s*$/);

This particular expression, broken down, reads like this:

/^   // Beginning of String
\s*  // Space, zero or more times
$/   // End of String

So it will test positive if there are zero or more spaces, from start to finish, and nothing else.

Upvotes: 2

Ash Burlaczenko
Ash Burlaczenko

Reputation: 25475

The code is fine. If you think its unreadable why not create the regex first

var regex = /^\s*$/;
if(regex.test($(this).val())
    ...

Upvotes: 2

user1115652
user1115652

Reputation:

/^\s*$/ is a regular expression literal and it has a test method which is being called. The brackets are from the if condition which is bigger.

Since javascript is fully object oriented even literals can have methods.

Upvotes: 2

ThiefMaster
ThiefMaster

Reputation: 318808

The code is correct:

/^\s*$/  // create a regex
  .test( // call the test method on it
    $(this) // create a jquery object
      .val() // call the val method on it
  )

However, the value could be cached: var val = $(this).val();. Then the line might be less confusing to you: /yourregex/.test(val)

Upvotes: 4

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