to all caps javascript code example

Example 1: javascript capitalize words

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

Example 2: uppercase javascript

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

Example 3: uppercase and lowercase letters in js

str.toLowerCase()
str.toUpperCase()