method take first letter in word in javascript code example

Example 1: get first word of string js

let myStr = "Hello World"
let firstWord = myStr.split(" ")[0]

Example 2: js get words first letter

var str = "Java Script Object Notation";
var matches = str.match(/\b(\w)/g); // ['J','S','O','N']
var acronym = matches.join(''); // JSON

console.log(acronym)