JuniorTheoryCommon

What does the program print?

JavaScript

console.log(0 == "", null == undefined, null === undefined);

true true false

Expecting 0 == "" to be false: == converts both sides to one type first, and the empty string becomes the number 0, so the two sides are equal.
Expecting null === undefined to be true: === never converts types, and null and undefined are different types, so it gives false.

JuniorTheoryCommon

JavaScript

console.log(0 == "", null == undefined, null === undefined);

true true false

Expecting 0 == "" to be false: == converts both sides to one type first, and the empty string becomes the number 0, so the two sides are equal.
Expecting null === undefined to be true: === never converts types, and null and undefined are different types, so it gives false.