What is the ‘Strict’ mode in JavaScript and how can it be enabled?

Question

What compulsions does  ‘Strict’ mode add to javascript? How to enable  ‘Strict’ mode in javascript.

Amreena Akhter · Answer

Strict mode in JavaScript is a way to run code with stricter rules, which helps catch errors and prevents unsafe actions.Enable it by adding:JavaScript"use strict";You can place it:At the top of a file (for whole script)Inside a function (for that function only)

Sandeep Dutta · Answer

Strict mode is a way to introduce better error-checking into your code. When you use strict mode, you cannot, for example, use implicitly declared variables, or assign a value to a read-only property, or add a property to an object that is not extensible.
You can enable strict mode by adding “use strict”; at the beginning of a file, a program, or a function. This kind of declaration is known as a directive prologue. The scope of a strict mode declaration depends on its context. If it is declared in a global context (outside the scope of a function), all the code in the program is in strict mode. If it is declared in a function, all the code in the function is in strict mode.