Lecture 164:- Strict Mode

Strict Mode is a way to enable a stricter version of JavaScript. It was introduced in ECMAScript 5 to make JavaScript code more secure and improve the quality of code. It helps catch common coding mistakes and makes it easier to write secure JavaScript code.

Strict Mode makes changes to how certain things work in JavaScript, such as changing the way variables are declared, making it an error to delete functions and variables, and raising an error when duplicate parameter names are used.

Strict Mode is activated by putting the string "use strict" at the beginning of a script or function. For example:

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"use strict"; function myFunction() {  var x = 10; }

In this example, myFunction() is in strict mode, which means that certain mistakes that would have previously been ignored by JavaScript will now be caught and result in an error.

Some benefits of using Strict Mode include:

• It catches common coding mistakes, such as using undeclared variables.
• It makes it easier to write secure JavaScript code by preventing the use of certain insecure coding practices.
• It makes JavaScript engines run faster because they can optimize the code better when they know it's in Strict Mode.