How can I determine if an element is contained in an Array without looping?

Question

How can I check whether a particular element is inside an array? I don't want to manually write a loop for this; instead I want to use a JavaScript built-in function, maybe something equivalent to

new Array(0,1,2,3,6,9,12,15,18).Contains(5)  //return false
new Array(0,1,2,3,6,9,12,15,18).Contains(1)   //return true

Answer 1

The Array object does have an indexOf function, that will return -1 if the object does not exist. However, IE does not support this function.

Regardless, how do you think it is going to locate the item under the scenes? It will have to loop! Just because there's a built-in function does not mean that it is magical.