A function test if an element is present in an Array.

f_Is_In_Array.js

// A function test if an element is present in an Array.
// Arrays.asList(Array).contains(string);
function f_Is_In_Array(elem, array, i) {
	var len;
	var indexOf = Array.prototype.indexOf;
	if (array) {
		if (indexOf) {
			return indexOf.call(array, elem, i);
		}

		len = array.length;
		i = i ? i < 0 ? Math.max(0, len + i) : i : 0;

		for (; i < len; i++) {
			// Skip accessing in sparse arrays
			if (i in array && array[i] === elem) {
				return i;
			}
		}
	}

	return -1;
};