If clause not working correctly

Question

I want to enter an if only if the value of a jquery object is empty and the dom element isn't a label or span. So i have

$('.container').children().each(function (index, item2){
    if ($(item2).val()=== '' && (item2.tagName.toLowerCase() !== 'label' || item2.tagName.toLowerCase() !== 'span')){
        //do stuff here
        console.log("tag: "+item2.tagName.toLowerCase());
    }
});

but in the console I get

tag: label

meaning that it's not working correctly. Am I missing something there?

Corrected it I want to enter the if when value is empty sorry to all — Apostolos
– Apostolos, Commented Mar 6, 2014 at 0:54

xdazz · Accepted Answer · 2014-03-05 10:39:48Z

2

Your condition is wrong, try below:

$('.container').children().each(function() {
    if ($(this).val() !== '' && !$(this).is('span') && !$(this).is('label')) {
        console.log("tag: "+item2.tagName.toLowerCase());
    }
});

But span and label doesn't has value attribute, if you mean to check whether the element has no children (including text nodes), there is :empty selector.

$('.container').children().each(function() {
    if (!$(this).is(':empty, span, label')) {
        console.log(this);
    }
});

Check the demo.

edited Mar 5, 2014 at 10:39

answered Mar 5, 2014 at 10:31

xdazz

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3 Comments

Brian North Over a year ago

You can also combine the label/span test to !$(this).is( 'span, label' )

A. Wolff Over a year ago

issue with second one is that an input, even with value, is always empty

Apostolos Over a year ago

I like the is method didn't know it

Rory McCrossan · Accepted Answer · 2014-03-05 10:29:23Z

1

If you want to enter the condition if the value isn't empty you need to use !== instead of ===.

if ($(item2).val() !== '' && (item2.tagName.toLowerCase() !== 'label' || item2.tagName.toLowerCase() !== 'span')) {
    // your code...
}

answered Mar 5, 2014 at 10:29

Rory McCrossan

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Comments

adeneo · Accepted Answer · 2014-03-05 10:38:17Z

1

I would rewrite that to

$('.container').children().each(function (index, item2){
    if ( item2.value ) {

    }
});

A span or a label has no value, so those will fail the condition anyway

edited Mar 5, 2014 at 10:38

answered Mar 5, 2014 at 10:31

adeneo

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2 Comments

adeneo Over a year ago

@A.Wolff - yeah, an empty string is falsy, so checking for length shouldn't really be neccessary.

A. Wolff Over a year ago

this is the most concise answer here and the less upvoted (not counting me in). Strange SO sometimes...

Ishan Jain · Accepted Answer · 2014-03-05 10:58:31Z

Your code is:

$('.container').children().each(function (index, item2){
   if ($(item2).val()=== '' && (item2.tagName.toLowerCase() !== 'label' || item2.tagName.toLowerCase() !== 'span')){           
     console.log("tag: "+item2.tagName.toLowerCase());
   }
});

Here you write your condition :- $(item2).val() === '' && (item2.tagName.toLowerCase() !== 'label' || item2.tagName.toLowerCase() !== 'span')

First of all if you want to allow non-empty value element use !== instead of using === (as @Rory McCrossan suggest).

Now we talk about your second condition i.e. - (item2.tagName.toLowerCase() !== 'label' || item2.tagName.toLowerCase() !== 'span')

means here you allow if element is LABEL OR SPAN.

So, your condition goes into following four ways -

(false || true ) ====>  true  // Element is label

(true || false ) ====>  true // Element is span

(true || true ) ====>  true // Element is not a span and not a label

(false || false ) ====>  false // Element is a span and also an label [this condition never satisfied]

I think, here you are wrong. You should use following condition (if you don't allow both type of element)-

$(item2).val() === '' && (item2.tagName.toLowerCase() !== 'label' && item2.tagName.toLowerCase() !== 'span')

In short you must use &&/AND instead of using ||/OR.

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