Scope Practice

For each exercise, tell me in what order each of the logs are executed, and what each of them will actually log.

In order to complete these exercises, you must understand the following concepts:

hoisting
variable assignment/reassignment vs. variable declaration
the three scoping levels: global, functional and block
the scoping levels that var/let/const adhere to
the order in which JavaScript is read and executed

let num = 10;

function foo() {
    if (num > 5) {
       num = 7;
    }
    console.log('A:', num);
}

foo();

console.log('B: ', num);

Bonus Challenges:

What would happen if we changed let to const?
What would happen if we added var in front of num = 7?

let grade = 100;

function losePoints() {
  grade = 90;

  function addPoints() {
    const grade = 95;

    if (grade === 95) {
      let grade = 97;
    }

    console.log('A: ', grade);
  }

  addPoints();

  console.log('B: ', grade);
}

losePoints();

console.log('C: ', grade);

var num = 5;

function first() {
  console.log('A: ', num);
  num = 6;
  console.log('B: ', num);
}

function second() {
  console.log('C: ', num);
  let num = 7;
}

first();
second();

console.log('D: ', num);

var instructor = 'Pam';

function changeInstructor() {

  console.log('A: ', instructor);

  if (instructor === 'Brittany') {
    const instructor = 'Nathaniel';
  } else {
    let instructor = 'Brittany';
  }

  console.log('B: ', instructor);

  function rename() {
    instructor = 'Louisa';
    console.log('C: ', instructor);
  }

  rename();

  console.log('D: ', instructor);

}

console.log('E: ', instructor);

changeInstructor();

console.log('F: ', instructor);

var shoe = 'flipflop';

function putOnShoe() {
  console.log('A: ', shoe);
  var shoe = 'boot';
}

console.log('B: ', shoe);
putOnShoe();
console.log('C: ', shoe);

brittanydionigi/scope.md

Scope Practice