Test your knowledge: Expressions and Operators

Review

1. Which item is an expression?

   price * quantity is an expression whose evaluation produces a value.
2. What value does (count = 3) produce?

   An assignment expression evaluates to the value assigned.
3. What does 10 === "10" produce?

   Number 10 and String "10" are different types, so strict equality produces false.
4. How many times does check() run in false && check()?

   The right operand is not evaluated when the left operand is falsy.
5. What does 0 ?? 10 produce?

   ?? falls back only for null or undefined, so it keeps 0.
6. What does 0 || 10 produce?

   0 is falsy, so || evaluates to the right operand 10.
7. Which operator chooses between two expressions based on a condition?

   The conditional operator uses condition ? whenTrue : whenFalse.
8. What does 2 + 3 * 4 evaluate to?

   The multiplication is evaluated before addition, producing 14. Parentheses can make alternate grouping explicit.
9. What does typeof 42 produce?

   typeof 42 produces the string "number".