JavaScript syntax: Difference between revisions

Revision as of 16:17, 17 April 2016

Revision as of 16:20, 17 April 2016

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[[Array data structure|Arrays]] are implemented so that only the defined elements use memory; they are "[[sparse array]]s". Setting <tt>{{Unstyled inline syntax|monospace=true|lang=javascript|code=myArray[10] = 'someThing'</tt>}} and <tt>{{Unstyled inline syntax|monospace=true|lang=javascript|code=myArray[57] = 'somethingOther'</tt>}} only uses space for these two elements, just like any other object. The <tt>length</tt> of the array will still be reported as 58.

One can use the object declaration literal to create objects that behave much like associative arrays in other languages: