Do not every say new Array() when creating a new JavaScript Array(). There are differences between creating an array in Javascript using the array literal, or the fully qualified “object” name (Array() vs []), and the bottom line is that the “right” way to do it is “[]” (array literal) instead of “new Array()”. Here is why:
- Most experienced JS programmers use []. [] is the way Douglas Crockford teaches it in JavaScript the Good Parts
(they even talk about it in JavaScript: The Definitive Guide
). Also, if you look in the unminified source for the jQuery library, you will never see Array().
- They appear to be nearly identical, except they aren’t.
- [] is more terse and readable, especially for nested arrays:
vs:
- Using the Array() keyword makes you think about arrays as being somehow different from plain vanilla JavaScript Objects (which, yes they are in-so-much as they are Objects with extra methods already defined for you). The literal helps you think about them more object-like because [] looks like {}. Plus, [] is more consistent with the way that you then access the array something[0] so there is less to remember.
- Most importantly, Array() doesn’t behave uniformly across argument numbers and types. ((new Array(X)).length === 1 for any X as long as typeof(X) != “number” else Array(X).length === X)
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