CODEWITHSUNDEEP
javascriptjquery
Henry
Henry

Reputation: 587

what jquery isArrayLike checks nodeType

There is a function named 'isArrayLike' in jquery which used by many functions for example $.each

function isArraylike( obj ) {
var length = obj.length,
    type = jQuery.type( obj );

if ( type === "function" || jQuery.isWindow( obj ) ) {
    return false;
}

if ( obj.nodeType === 1 && length ) {
    return true;
}

return type === "array" || length === 0 ||
    typeof length === "number" && length > 0 && ( length - 1 ) in obj;

}

I know it is used to see whether it is like an array,but i do not know why the second if.

It checks nodeType to make sure it's an element and why length?Is an element have length property?

Thx

Upvotes: 1

Views: 376

Answers (1)

guest
guest

Reputation: 6698

If you find undocumented code that doesn't make sense, one thing you can do is look at why someone wrote it in the first place. Here's the commit that adds the nodeType check:

https://github.com/jquery/jquery/commit/3c7f2af81d877b24a5e5b6488e78621fcf96b265

Judging by the test that they added with it, it's to support form elements, which it will treat as an array of controls.

Upvotes: 2

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