Question

Is there a way in Javascript to get a list or dump the contents of all global variables declared by Javascript/jQuery script on a page? I am particularly interested in arrays. If I can get the array names, it will be enough to me. Seeing its values is a bonus.

Answer 1

Object.keys( window );

This will give you an Array of all enumerable properties of the window object, (which are global variables).

For older browsers, include the compatibility patch from MDN.

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To see its values, then clearly you’ll just want a typical enumerator, like for-in.

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You should note that I mentioned that these methods will only give you enumerable properties. Typically those will be ones that are not built-in by the environment.

It is possible to add non-enumerable properties in ES5 supported browsers. These will not be included in Object.keys, or when using a for-in statement.

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As noted by @Raynos, you can Object.getOwnPropertyNames( window ) for non-enumerables. I didn’t know that. Thanks @Raynos!

So to see the values that include enumerables, you’d want to do this:

var keys = Object.getOwnPropertyNames( window ),
    value;

for( var i = 0; i < keys.length; ++i ) {
    value = window[ keys[ i ] ];
    console.log( value );
}