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};

1function capitalizeFirstLetter(string) {
2  return string.charAt(0).toUpperCase() + string.slice(1);
3}
4
5console.log(capitalizeFirstLetter('foo bar bag')); // Foo

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

1const str = 'captain picard';
2
3function capitalize(str) {
4  return str.charAt(0).toUpperCase() + str.slice(1);
5}
6
7const caps = str.split(' ').map(capitalize).join(' ');
8caps; // 'Captain Picard'

1function capitalizeFirstLetter(string) {
2  return string.charAt(0).toUpperCase() + string.slice(1);
3}
4
5console.log(capitalizeFirstLetter('foo')); // Foo

1const string = "tHIS STRING'S CAPITALISATION WILL BE FIXED."
2const string = string[0].toUpperCase() + string.slice(1)