Anti caps

main.js

var isCaps = function(letter) {
	return letter === letter.toUpperCase();
};

var antiCaps = function(str) {

	if (!str && str.length <= 0) {
		console.log('Please use a string');
	}

	var newStr = '';

	for (var i = 0; i < str.length; i++) {
		var letter = str[i];

		if (isCaps(letter)) {
			letter = letter.toLowerCase();
		} else {
			letter = letter.toUpperCase();
		}

		newStr += letter;
	}

	return newStr;
};

console.log(antiCaps('WordTocapiTALIZe'));