let val = '1000';

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

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

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