If a=1, b=2, c=3,....z=26. Given a string, find all possible codes that string can generate. Give a count as well as print the strings. For example: Input: "1123". You need to general all valid alphabet codes from this string.

combo.js

// js implementation

function combination(stringOfNum) {
	if (stringOfNum.length == 1) {
		return 1;
	} else {
		var res = [];
		res[0] = 1;
		for (var n = 1; n < stringOfNum.length; n++) {
			var condition = (parseInt(stringOfNum.slice(-2)) <= 26) ? 1 : 0;
			res[n] = res[n-1] + condition;
		}
		return res[stringOfNum.length - 1];
	}
}