17. ECMAScript 3 is fully supported in all browsers.
ECMAScript 5 is fully supported in all modern browsers.(IE9 does
not support ES5)
18.
19.
20.
21. var i = 5;
for (var i = 0; i < 10; i++) {
// some statements
}
// Value of i is …
let i = 5;
for (let i = 0; i < 10; i++) {
// some statements
}
// Value of i is...