js find string starting with code example

Example 1: js start with

const str = 'Linux is great';
console.log(str.startsWith('Linux is'));// true
console.log(str.startsWith('Windows is'));// false
console.log(str.startsWith('ux is', 3));// true

Example 2: javascript string starts with

//checks if a string starts with a word
function startsWith(str, word) {
    return str.lastIndexOf(word, 0) === 0;
}
startsWith("Welcome to earth.","Welcome"); //true