nextInArray

nextInArray.js

/* 
 * Returns the next element in a function. 
 * Automatically rotates the index to the first element, if value matched the last element.
 * If no match found for value returns the first element.	
 */

var nextInArray = function (value,anArray){
	//TODO : Check if anArray is really an array.	
	var index = anArray.indexOf(value);	
	if ( index == anArray.length-1 || index == -1 ) {
		return anArray[0];
	}
	else {
		return anArray[(index+1)];
	}
}

//Usage
myArray = ["a","b","z"];
nextInArray("a",myArray) // returns "b"
nextInArray("z",myArray) // returns "a"
nextInArray("1",myArray) // returns "a"