Javascript Array.include and Array.index

Just needed them and poor JS lacks these basic functions…

Warning:
if(![‘hello’].index(‘hello’))alert(‘watch out because 0 is false‘);

Array.prototype.index = function(val) {
  for(var i = 0, l = this.length; i < l; i++) {
    if(this[i] == val) return i;
  }
  return null;
}

Array.prototype.include = function(val) {
  return this.index(val) !== null;
}

3 thoughts on “Javascript Array.include and Array.index”

pragmatig says:

2008-03-13 at 15:42:05

Comment went to the wrong post, wordpress bug?

jafferhaider.wordpress.com:
Wouldn’t it be better if you returned -1 instead of null in the index function?

Its build to be ruby-like:
Array.index: “Returns the index of the first object in self such that is == to obj. Returns nil if no match is found.”

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Jaffer Haider says:

2008-03-15 at 18:16:33

*double checks the title of the post* 😉

Ah ok, makes sense.

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Thomas says:

2010-06-21 at 15:09:31

Simple and efficient!

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