jQuery inArray verification problems

Question

My inArray jQuery verification dosen't work :

The html :

<input type="text" name="number" class="verify" conditions="requierd numeric"/>
<input type="text" name="number2" class="verify" conditions="requierd string"/>

The jQuery code with my inArray verification :

    $('input.verify').blur(function(){
        var conditions = $(this).attr('conditions').split(' ');
            if($.inArray('requierd', conditions)){
                alert('ok');
            }
    });

but when i put === false behind my condition it work !

    $('input.verify').blur(function(){
        var conditions = $(this).attr('conditions').split(' ');
            if($.inArray('requierd', conditions) === false){
                alert('ok');
            }
    });

Why ?

Thanks

Community · Accepted Answer · 2020-06-20 09:12:55Z

1

Official documentation says:

returns -1 when it doesn't find a match. If the first element within the array matches value, $.inArray() returns 0.

Because JavaScript treats 0 as loosely equal to false (i.e. 0 == false, but 0 !== false), if we're checking for the presence of value within array, we need to check if it's not equal to (or greater than) -1.

edited Jun 20, 2020 at 9:12

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answered Aug 28, 2012 at 14:49

Sergii

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Comments

Mitya · Accepted Answer · 2012-08-28 14:49:49Z

0

Like with indexOf(), $.inArray must be checked against -1. Otherwise, if the element is not found, it will return -1 which i s a truthy value, i.e. it will resolve your condition to true.

In short:

if ($.inArray('something', array) != -1)

Note though that you don't really need to split the conditions string - you could use a REGEX with a word boundary.

if (/\brequired\b/.test($(this).attr('conditions')) { /* code */ }

Finally, you should use data- attributes rather than just inventing custom attributes, as the latter will invalidate your HTML.

answered Aug 28, 2012 at 14:49

Mitya

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Comments

João Silva · Accepted Answer · 2012-08-28 14:51:03Z

0

$.inArray() will return -1 if the element is not found, which will evaluate to true. Either use:

if (~$.inArray('requierd', conditions))

This will work because ~-1 == 0 == false. Or, as an alternative, and by far the most common:

if ($.inArray('requierd', conditions) != -1)

answered Aug 28, 2012 at 14:51

João Silva

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