I know that you can use ${} inside a string to put a var but here it seems it doesn't want to recognise the var and it is not in the brackets
var str = s.toLowerCase();
var counts = {};
var ch, index, len, count;
for (index = 0, len = str.length; index < len; ++index) {
ch = str.charAt(index);
count = counts[ch];
counts[ch] = count ? count + 1 : 1;
}
for (ch in counts) {
console.log('${ch}(${counts[ch]})');
}
'with`