Types & Equality

Question 1

What does the below code print out?

    if (undefined == null) {
        console.log("Moo")
    } else {
        console.log("Zoo")
    }

Answer 1

They are actually values that can be checked for equality

Moo

Question 2

// What does the below code print out?
    console.log(typeof(null));

Answer 2

It should be “null” but javascript incorrectly reports the type of null as “object”.

object

Question 3

// What does the below code print out?
    if (undefined === null) {
        console.log("Moo")
    } else {
        console.log("Zoo")
    }

Answer 3

undefined and null are not the same types so === will return false

Zoo

Question 4

// What will the below code print out?
    console.log(NaN == "1");

Answer 4

NaN equal to ANYTHING is always false, even when compared to itself

False