const_keyword_intro.js

// Let's declare a variable named "facebookURL"
const facebookURL = 'https://www.facebook.com/';

// If you try to change its value then the compiler or web browser will throw an error
facebookURL = 'facebook.com';

// Uncaught TypeError: Assignment to constant variable.

// Now let's declare a variable within a loop
for(const j = 0; j < 10; j++) {
	// Variable "j" can be accessible within this loop
	// But it will only be printed once
	// i.e; 0. The rest values will not be assigned.
	console.log(j);
	
	// Uncaught TypeError: Assignment to constant variable after one loop.
}

// Now let's print this "j" outside the "for" loop
console.log(j);

// The compiler or web browser will throw an error if you try to print the value of "j" outside the "for" loop:
// Uncaught ReferenceError: j is not defined