Swap string case
function swapCase(text) {
var arr = text.split('');
var rev = [];
for (var i = 0; i < arr.length; i++) {
if ( arr[i] == arr[i].toUpperCase()){
rev.push(arr[i].toLowerCase());
}
if ( arr[i] == arr[i].toLowerCase()){
rev.push(arr[i].toUpperCase());
}
};
return rev.join('');
}