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Version: 3.27.2

Array.prototype.keys()

The keys() method returns a new Array Iterator object that contains the keys for each index in the array.

Syntax​

keys()

Return value​

A new Array iterator object.

Description​

When used on sparse arrays, the keys() method iterates empty slots as if they have the value undefined.

The keys() method is generic. It only expects the this value to have a length property and integer-keyed properties.