let val = "1000";

(function () {
    let val = "100"; // local scope variable
    console.log(val);
})();

let result = (function () {
    let val = "Laurence";
    return val;
})();
console.log(result);
console.log(val);

(function (val) {
    console.log(`My name is ${val}`);
})("Laurence");