how to capitalize string in js code example

Example 1: uppercase javascript

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

Example 2: first letter tuUppercase

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

Example 3: javascript capitalize

myString = 'the quick green alligator...';
myString.replace(/^\w/, (c) => c.toUpperCase());

myString = '    the quick green alligator...';
myString.trim().replace(/^\w/, (c) => c.toUpperCase());