Compare Scopes of the var and let Keywords

Summary

When using the let keyword, the scope is limited to that block, statement, or expression.

Final Code

function checkScope() {
  let i = 'function scope';
  if (true) {
    let i = 'block scope';
    console.log('Block scope i is: ', i);
  }
  console.log('Function scope i is: ', i);
  return i;
}