immediately invoked function javascript

1(() => {
2  // statements
3})();

1result = (function(a, b){
2    return a - b;
3})(100, 42);
4
5console.log(result); // 58

1(function() {
2  /* */
3})()
4

1(() => {
2  /* */
3})()
4

1(function () {
2    var aName = "Barry";
3})();
4// Variable aName is not accessible from the outside scope
5aName // throws "Uncaught ReferenceError: aName is not defined"
6