options to change uppercase of string js code example

Example 1: uppercase javascript

var str = "Hello World!";
var res = str.toUpperCase();  //HELLO WORLD!

Example 2: title case javascript

function titleCase(str) {
    return str
        .split(' ')
        .map((word) => word[0].toUpperCase() + word.slice(1).toLowerCase())
        .join(' ');
}
console.log(titleCase("I'm a little tea pot")); // I'm A Little tea Pot