App Dev Worksheet: Functions

App development lesson 20: Functions · Set 559 · 40 questions

Developer's tip (Write once, use often): function name(parameter) { …; return result; } — call it with name(value). Work out each call separately, then finish the line. Inside a function, if / return can give different results for different inputs.

NameDateTime takenScore ___ / 40

1.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(1));
2.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(0));
3.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(37));
4.🧰 A museum app works out the entry fee. What number does this code show?
function fee(age) {
  if (age < 5) {
    return 0;
  }
  return 30;
}
show(fee(5) + fee(1));
5.🧰 What does return do in a function? (a) deletes the app (b) repeats the code (c) sends back a value (d) closes the screen
6.🧰 A museum app works out the entry fee. What number does this code show?
function fee(age) {
  if (age < 5) {
    return 0;
  }
  return 50;
}
show(fee(3) + fee(10));
7.🧰 In function tip(bill), what is bill? (a) a screen (b) an event (c) a parameter (d) a loop
8.🧰 A museum app works out the entry fee. What number does this code show?
function fee(age) {
  if (age < 5) {
    return 0;
  }
  return 60;
}
show(fee(9) + fee(2));
9.🧰 What is a function? (a) a list of colours (b) a named block of code (c) a screen size (d) a type of phone
10.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(24));
11.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(10, 2));
12.🧰 A museum app works out the entry fee. What number does this code show?
function fee(age) {
  if (age < 5) {
    return 0;
  }
  return 30;
}
show(fee(4) + fee(4));
13.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(4));
14.🧰 How do you run (call) a function called greet? (a) #greet (b) greet() (c) greet[] (d) run greet
15.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(30));
16.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(9));
17.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Aman")); (a) greet (b) Aman (c) Hello, Aman! (d) Hello, name!
18.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(15, 6));
19.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Meera")); (a) Meera (b) Well done, name! (c) greet (d) Well done, Meera!
20.🧰 A museum app works out the entry fee. What number does this code show?
function fee(age) {
  if (age < 5) {
    return 0;
  }
  return 60;
}
show(fee(3) + fee(6));
21.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(2));
22.🧰 Why write a function? (a) to hide errors (b) to make code longer (c) to slow the app (d) to reuse code
23.🧰 A museum app works out the entry fee. What number does this code show?
function fee(age) {
  if (age < 5) {
    return 0;
  }
  return 60;
}
show(fee(12) + fee(5));
24.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Aman")); (a) Welcome, name! (b) greet (c) Welcome, Aman! (d) Aman
25.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(5));
26.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(25, 6));
27.🧰 What does this code show?
function greet(name) {
return "Hi, " + name + "!";
}
show(greet("Aman")); (a) Hi, name! (b) greet (c) Hi, Aman! (d) Aman
28.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(32));
29.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(35, 6));
30.🧰 A museum app works out the entry fee. What number does this code show?
function fee(age) {
  if (age < 5) {
    return 0;
  }
  return 30;
}
show(fee(12) + fee(12));
31.🧰 A museum app works out the entry fee. What number does this code show?
function fee(age) {
  if (age < 5) {
    return 0;
  }
  return 20;
}
show(fee(8) + fee(9));
32.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(2));
33.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(7));
34.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(12));
35.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(50, 3));
36.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(5));
37.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(55, 2));
38.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Zoya")); (a) Welcome, name! (b) greet (c) Welcome, Zoya! (d) Zoya
39.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Riya")); (a) Riya (b) greet (c) Hello, name! (d) Hello, Riya!
40.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(0));

Answer key

70
20
111
30
sends back a value
50
a parameter
60
a named block of code
72
20
0
80
greet()
90
18
Hello, Aman!
90
Well done, Meera!
60
50
to reuse code
120
Welcome, Aman!
80
150
Hi, Aman!
96
210
60
40
60
14
24
150
110
110
Welcome, Zoya!
Hello, Riya!
40

Free app development lessons, practice and worksheets at talentjr.in/app-development-for-students