PermutationCheck_Solution2.js

function isPermutation(strA, strB){
	var isValid = true;
	
	//First validity check
	if (!strA || !strB || strA.length !== strB.length){
		return !isValid;
	}
	
	var sortedA = sort(strA), sortedB = sort(strB);
	
	return sortedA === sortedB;
}

function sort(str){
	return str.split("").sort().toString();;
}