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

Answer:

Strict mode is a way to introduce better error-checking into your code.

• When you use strict mode, you cannot 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.

Example:

Declared inside a function, it has local scope (only the code inside the function is in strict mode):

x = 3.14;
// This will not cause an error as variable x is not defined and the code is not in strict mode.
myFunction();
function myFunction() {
"use strict";
y = 3.14;
// This will cause an error beacause variable y is not defined and we are using strict mode
}

from the above code, you can understand strict mode.