CODEWITHSUNDEEP
jqueryhtmlif-statement
grandel
grandel

Reputation: 31

Jquery Else Statement not working

My problem is that the else section here doesn't seem to work. I already surfed the web for a solution and even though there are very many questions exactly like mine, the answer always seems to be different.

This is the button I click on

<input type="submit" value="4">

I also have a button like this:

<input type="submit" id="b1" value="Back">

My Aim is to find out if the button with an ID was clicked or not.

var specify = "";
var prevpos = 0;

$('input[type=submit]').click(function(){
    specify = $(this).attr('value');

    if($(this).attr('id').substring(0,1) == "b")
    {
       $("html, body").animate({scrollTop: prevpos}, 777);
       $(".right").animate({opacity: 0.0}, 200);
       $(".left").animate({opacity: 1.0}, 200);
       // more stuff here                           
    }   
    else
    {
       $("html, body").animate({scrollTop: prevpos}, 777);  
       // more stuff here
    }
});

As always, any help is greatly appreciated!

Upvotes: 0

Views: 169

Answers (3)

hradac
hradac

Reputation: 2491

I had a similar requirement some time ago and here's my solution:

var specify = "";
var prevpos = 0;

$('input[type=submit]').click(function(e){ //Note the addition of 'e'
    var id = e.target.id; // If the element has no ID you should get an empty string here

    specify = $(this).attr('value');

    if( id.match(/^b/) ) { // This is a regular expression, if the ID starts with 'b' then it matches
       $("html, body").animate({scrollTop: prevpos}, 777);
       $(".right").animate({opacity: 0.0}, 200);
       $(".left").animate({opacity: 1.0}, 200);
       // more stuff here                           

    } else {
       $("html, body").animate({scrollTop: prevpos}, 777);  
       // more stuff here
    }
});

Upvotes: 0

Rory McCrossan
Rory McCrossan

Reputation: 337590

The problem with your code is because when you click the button without an id you are calling substr() on a null, which will cause errors.

Try this instead:

var specify = "";

$('button').click(function () {
    specify = $(this).attr('value');
    var id = $(this).attr('id');

    // check there is an id, and if so see if it begins with 'b'
    if (id && id.substring(0, 1) == "b") {
        alert("You clicked the button WITH an id");
    } 
    else {
        alert("You clicked the button WITHOUT an id");
    }
});

Example fiddle

Upvotes: 4

Luceos
Luceos

Reputation: 6730

var specify = "";
var prevpos = 0;

$('input[type=submit]').click(function(){
    specify = $(this).attr('value');

    if($(this).attr('id') && $(this).attr('id').substring(0,1) == "b")
    {
       $("html, body").animate({scrollTop: prevpos}, 777);
       $(".right").animate({opacity: 0.0}, 200);
       $(".left").animate({opacity: 1.0}, 200);
       // more stuff here                           
    }   
    else
    {
       $("html, body").animate({scrollTop: prevpos}, 777);  
       // more stuff here
    }
});

You probably need to check whether the element has the id attribute at all before checking on its value.

Upvotes: 2

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