Calling a function
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. Which line runs the function sayHello?
2. A function is declared but never called. What happens to its code?
3. After declaring function sayHello(), you write sayHello(); three times. How many times does it run?
4. Which is correct? A function declaration is written first, then the call comes below it.
5. True or false: in JavaScript, you can call a function before its declaration appears in the file.
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1sayHello(); | AThe brackets are missing, so the function is not called and its code does not run. It should be sayHello(); | |
| 2for (let i = 0; i < 3; i++) { sayHello(); } | BsayHello(); sayHello(); | |
| 3You can call the same function twice to run its code twice | Cfunction sayHello() { console.log('Hi!'); } sayHello(); | |
| 4A function must be declared before it is called, or its declaration must be available when the call runs | DThe call inside the loop has no brackets, so sayHello never runs three times. It should be sayHello(); inside the loop. | |
| 5sayHello; | ECalls the function sayHello, so the code inside it runs once | |
| 6for (let i = 0; i < 3; i++) { sayHello; } | FCalls sayHello three times by placing the call inside a loop |
C
Definitions
functionName()
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
function sayHello() { console.log("Hi!"); }
________();
2.
function sayHello() { console.log("Hi!"); }
sayHello_);
3.
sayHello();
________ sayHello() { console.log("Hi!"); }
4.
function cheer() { console.log("Go!"); }
___ (let i = 0; i < 3; i++) cheer();
5.
let n = 0;
_____ (n < 2) { sayHello(); n++; }
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
sayHello();
B
sayHello();
C
sayHello;
D
function sayHello() {
E
console.log("Hello!");
F
}
Question 2
A
sayHelo();
B
sayHello();
C
function sayHello() {
D
console.log("Hello!");
E
}
Question 3
A
for (let i = 0; i < 3; i++) {
B
console.log("Round " + i);
C
Cheer();
D
}
E
function cheer() {
F
console.log("Go!"); }
Question 4
A
call greet();
B
greet();
C
function greet() {
D
console.log("Hi!");
E
}
Question 5
A
function sayBye() {
B
console.log("Bye!"); }
C
sayBye(;
D
sayBye();
Answer Key
Calling a function
Section A: Quick Questions
Q1
A — sayHello();
Q2
A — It does not run
Q3
B — 3 times
Q4
A — function sayHello() { console.log('Hi'); } sayHello();
Q5
B — True
Section B: Match the Pairs
Q1
sayHello(); → Calls the function sayHello, so the code inside it runs once
Q2
for (let i = 0; i < 3; i++) { sayHello(); } → Calls sayHello three times by placing the call inside a loop
Q3
You can call the same function twice to run its code twice → sayHello();
sayHello();
Q4
A function must be declared before it is called, or its declaration must be available when the call runs → function sayHello() { console.log('Hi!'); }
sayHello();
Q5
sayHello; → The brackets are missing, so the function is not called and its code does not run. It should be sayHello();
Q6
for (let i = 0; i < 3; i++) {
sayHello;
} → The call inside the loop has no brackets, so sayHello never runs three times. It should be sayHello(); inside the loop.
Section C: Definitions
Q1
functionName() — Calling a function: write its name followed by brackets, like sayHello(), to run its code. You can call it as many times as you like. Without the brackets, it does not run.Section D: Fill in the Blanks
Q1
function sayHello() { console.log("Hi!"); }
sayHello();Q2
function sayHello() { console.log("Hi!"); }
sayHello();Q3
sayHello();
function sayHello() { console.log("Hi!"); }Q4
function cheer() { console.log("Go!"); }
for (let i = 0; i < 3; i++) cheer();Q5
let n = 0;
while (n < 2) { sayHello(); n++; }Section E: Spot the Error
Q1
C — Line 3 has no brackets, so the function is not called and nothing prints. It should be sayHello(); and it works even before the declaration.
Q2
A — The function name is spelled wrongly on line 1, so JavaScript can't find it (ReferenceError). It should be sayHello();.
Q3
C — Names are case sensitive. The function is called cheer, not Cheer, so line 3 should be cheer();.
Q4
A — JavaScript has no call keyword. To call a function you write its name and brackets only, so line 1 should be greet();.
Q5
C — The call on line 3 is missing its closing bracket. It should be sayBye(); with both brackets.