array.contains()
Returns the position of the first element in the array that matches the item that we are searching for, or 0 if the item is not found.
array.contains( needle=object, substringMatch=boolean )
Returns: Number
Examples
fruits = ["apple","orange","BANANA","banana","orange","Banana","Orange"];
writeDump(fruits.contains("banana"));
writeDump(fruits.contains("Orange"));