typeof Operator
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. Does typeof return a string naming a value's data type?
2. Is 'type' by itself a valid JavaScript operator?
3. Must 'typeof' be written in lowercase?
4. Can typeof be used on a variable or a direct value like 42?
5. Does typeof true return "boolean"?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1typeof "hello" | Atypeof true | |
| 2typeof 42 | BWrong - the full operator is 'typeof', not 'type' | |
| 3Checks the data type of a value | Ctypeof | |
| 4Returns a string naming a boolean's type | DReturns "string" | |
| 5console.log(Typeof name); | EWrong - 'typeof' must be lowercase | |
| 6console.log(type age); | FReturns "number" |
C
Definitions
typeof
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
console.log(______ name);
2.
console.log(______ age);
3.
let result = ______ isReady;
4.
console.log(______ 42);
5.
let kind = ______ "hi";
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
let x = 5;
B
console.log(type x);
C
let y = true;
Question 2
A
console.log(Typeof name);
B
let name = "Amy";
C
let age = 10;
Question 3
A
let flag = true;
B
console.log(typeof(flag));
C
console.log(typeof flag);
Question 4
A
console.log(typeofn);
B
let n = 5;
C
console.log(typeof n);
Question 5
A
let s = "hi";
B
console.log(typeof s);
C
console.log(typof s);
Answer Key
typeof Operator
Section A: Quick Questions
Q1
A — Yes
Q2
B — No
Q3
A — Yes
Q4
A — Yes
Q5
B — Yes
Section B: Match the Pairs
Q1
typeof "hello" → Returns "string"
Q2
typeof 42 → Returns "number"
Q3
Checks the data type of a value → typeof
Q4
Returns a string naming a boolean's type → typeof true
Q5
console.log(Typeof name); → Wrong - 'typeof' must be lowercase
Q6
console.log(type age); → Wrong - the full operator is 'typeof', not 'type'
Section C: Definitions
Q1
typeof — An operator that returns a string naming the data type of a value.Section D: Fill in the Blanks
Q1
console.log(typeof name);Q2
console.log(typeof age);Q3
let result = typeof isReady;Q4
console.log(typeof 42);Q5
let kind = typeof "hi";Section E: Spot the Error
Q1
B — The operator is 'typeof', not just 'type'.
Q2
A — 'typeof' must be lowercase - a capital T causes an error.
Q3
B — This line is actually correct - typeof can be used with or without parentheses.
Q4
A — Missing space between 'typeof' and the variable name.
Q5
C — 'typeof' is misspelled as 'typof'.