Strict mode intentionally has different semantics than normal code we're used to.
"use strict"the syntax for strict mode- Catches silent errors and throws them
- Doesn't allow you to use certain syntax that could possibly be defined in future versions of ECMAScript.
- es6 JS modules are automatically converted to strict mode
- If the 'this' keyword ever references the global object in browser, strict mode returns undefined.
- Doesn't allow global variables. For example:
name = ‘tyler’ // throws a reference error