Curly braces and indentation
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. Which if statement uses curly braces correctly?
2. Where does the opening brace usually go in a for loop?
3. Where does the closing brace } go?
4. Which function is indented correctly?
5. True or false: Curly braces { } group the statements that belong to an if, loop or function.
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1if (score > 50) { console.log("Pass"); } | AThe opening brace { sits on the same line as the if. The statement inside the braces is indented, and the closing brace } sits on its own line. | |
| 2for (let i = 0; i < 3; i++) { console.log(i); } | Bfunction greet() { console.log("Hi"); } | |
| 3Curly braces group all the statements that belong to a function, and the body is indented inside them. | CThe braces group the statements that repeat in the loop. Only the indented code inside { } runs each time. | |
| 4Several statements can share one block. Every line inside the braces is indented the same amount. | DThe opening brace is not on the same line as the if, and the statement inside is not indented, so the block is hard to read. | |
| 5if (age >= 13) { console.log("Teen"); | EThe closing brace } is missing. Every opening { needs a matching } on its own line after the block. | |
| 6if (age >= 13) { console.log("Teen"); } | Fwhile (lives > 0) { lives--; console.log(lives); } |
C
Definitions
{ }
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
if (score >= 50) _
console.log("Pass");
}
2.
for (let i = 0; i < 3; i++) {
console.log(i);
_
3.
function sayHi() _
console.log("Hi!");
}
4.
function double(n) {
______ n * 2;
}
5.
while (lives > 0) {
lives--;
_
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
function pass(score) {
B
return score > 50;
C
)
Question 2
A
function add(a, b)
B
return a + b;
C
}
Question 3
A
let ok = true;
B
if (ok) [
C
console.log("Go");
D
}
Question 4
A
let n = 3;
B
while (n > 0) (
C
console.log(n);
D
n--;
E
}
Question 5
A
function isEven(num) {
B
if (num % 2 === 0) {
C
return true;
D
)
E
return false;
F
}
Answer Key
Curly braces and indentation
Section A: Quick Questions
Q1
A — if (score > 10) {
console.log("Win");
}
Q2
A — On the same line as the for (...) part
Q3
A — On its own line, lined up with the start of the if, loop or function
Q4
B — function greet() {
console.log("Hi");
}
Q5
B — True
Section B: Match the Pairs
Q1
if (score > 50) {
console.log("Pass");
} → The opening brace { sits on the same line as the if. The statement inside the braces is indented, and the closing brace } sits on its own line.
Q2
for (let i = 0; i < 3; i++) {
console.log(i);
} → The braces group the statements that repeat in the loop. Only the indented code inside { } runs each time.
Q3
Curly braces group all the statements that belong to a function, and the body is indented inside them. → function greet() {
console.log("Hi");
}
Q4
Several statements can share one block. Every line inside the braces is indented the same amount. → while (lives > 0) {
lives--;
console.log(lives);
}
Q5
if (age >= 13) {
console.log("Teen"); → The closing brace } is missing. Every opening { needs a matching } on its own line after the block.
Q6
if (age >= 13)
{
console.log("Teen");
} → The opening brace is not on the same line as the if, and the statement inside is not indented, so the block is hard to read.
Section C: Definitions
Q1
{ } — Curly braces group the statements that belong to an if, loop or function. The code inside the braces is indented so you can see which block it belongs to.Section D: Fill in the Blanks
Q1
if (score >= 50) {
console.log("Pass");
}Q2
for (let i = 0; i < 3; i++) {
console.log(i);
}Q3
function sayHi() {
console.log("Hi!");
}Q4
function double(n) {
return n * 2;
}Q5
while (lives > 0) {
lives--;
}Section E: Spot the Error
Q1
C — The function block is closed with a round bracket. It must be closed with a curly brace } on its own line.
Q2
A — The opening curly brace { is missing. It should go at the end of the first line: function add(a, b) {
Q3
B — A square bracket [ was used to open the block. An if block must open with a curly brace { on the same line as the if.
Q4
B — A round bracket ( was used to open the loop body. A block must open with a curly brace {.
Q5
D — The if block is closed with a round bracket. It must be closed with a curly brace }, on its own line, lined up with the if.