let_keyword_intro.js

// Let's declare a variable named "emailAddress"
let emailAddress = 'someone@example.com';

// If accidentally we redeclare anathor variable with the same name,
// then the compiler will throw an error, which is indeed a great practice.
let emailAddress = 'abc';

// Uncaught SyntaxError: Identifier 'emailAddress' has already been declared

// Now let's declare a variable within a loop
for(let i = 0; i < 10; i++) {
	// Variable "i" can be accessible within this loop
	console.log(i);
}

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

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