Booleans 15

Question 1

What are the 3 ways to convert an arbitrary value into a boolean?

Answer 1

Boolean(x) (recommended of the 3)
x ? true : false (conditional operator)
!!x (logical not operator)

Question 2

What are truthy and falsy values?

Answer 2

values that are true/false when coerced into booleans

Question 3

What are the two logical binary operators?

What is special about them?

Answer 3

logical or (||)
logical and (&&)

they are value preserving and short-circuiting

value preserving: the operands are evaluated as booleans but returned unchanged

short-circuiting: if the first operand determines the result, the second operand will not be evaluated. (this is also the case with the conditional operator ? : )

Question 4

Why is || logical or legacy compared to ?? nullish operator?

Answer 4

Because logical or will move on if the first operand is any falsy value, while nullish operator will only move on if it is undefined or null.