“Use strict” is a directive in JavaScript that enables strict mode. Strict mode is a way to opt into a restricted variant of JavaScript which does not allow certain actions and throws more exceptions. It’s a string that is put at the beginning of a script or a function to enforce stricter parsing and error handling on your JavaScript code at runtime.
The purpose of “use strict” is to indicate that the code should be executed in strict mode. With strict mode, you can not, for example, use undeclared variables, or read-only global variables. This helps make your code more robust, maintainable, and predictable.
Here’s an example:
“use strict”; x = 3.14;
// This will cause an error because x is not declared
In the example above, the code will produce an error because you are trying to assign a value to an undeclared variable x, which is not allowed in strict mode.
