capitalize first carater js

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 lower = 'this is an entirely lowercase string';
2const upper = lower.charAt(0).toUpperCase() + lower.substring(1);

1const capitalize = (s) => {
2  if (typeof s !== 'string') return ''
3  return s.charAt(0).toUpperCase() + s.slice(1)
4}
5
6capitalize('flavio') //'Flavio'
7capitalize('f')      //'F'
8capitalize(0)        //''
9capitalize({})       //''
10

1p.capitalize {
2  text-transform: capitalize;
3}

1String.prototype.capitalize = function() {
2  return this.charAt(0).toUpperCase() + this.slice(1)
3}
4