uppercase the first letter of a string using javascript 2f

1//capitalize only the first letter of the string. 
2function capitalizeFirstLetter(string) {
3    return string.charAt(0).toUpperCase() + string.slice(1);
4}
5//capitalize all words of a string. 
6function capitalizeWords(string) {
7    return string.replace(/(?:^|\s)\S/g, function(a) { return a.toUpperCase(); });
8};

1const name = 'avengers'
2const userName = name.charAt(0).toUpperCase() + name.slice(0)
3
4console.log(userName)
5// Output: Aavengers