JavaScript - Palabra mayúscula y minúscula

function camel(cadena){

	var sCadena = cadena;

	var i;

	var c;

	var caracter= ' ';

        for (i=0; i < sCadena.length; i++) {

		c = sCadena.charAt(i);

		if (caracter.isUpperCase(c)) {

			sCadena.setCharAt(i, caracter.toLowerCase(c));

		} else {

			sCadena.setCharAt(i, caracter.toUpperCase(c));

		}

	}

	return sCadena;

}

function camel(cadena){

	var sCadena = [];

	for (var i=0, t=cadena.length; i <t; i++) {

		var c = cadena.charAt(i);

		if ( (i+1)%2 ) {

			sCadena.push(c.toUpperCase());

		} else {

			sCadena.push(c.toLowerCase());

		}

	}

	return sCadena.join('');

}

console.log(camel('Hola'));

function camelCase(cadena){

	var sCadena = cadena.split(' ');

	sCadena = sCadena.map(function(palabra){

		return palabra.charAt(0).toUpperCase() + palabra.slice(1);

	});

	return sCadena.join('');

}

console.log(camelCase('hola mundo'));