App Dev Worksheet: Functions

App development lesson 20: Functions · Set 538 · 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 double(n) {
return n * 2;
}
show(double(16));
2.🧰 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(2) + fee(12));
3.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(60, 2));
4.🧰 What is a function? (a) a named block of code (b) a screen size (c) a list of colours (d) a type of phone
5.🧰 What does this code show?
function greet(name) {
return "Hi, " + name + "!";
}
show(greet("Zoya")); (a) Zoya (b) Hi, Zoya! (c) greet (d) Hi, name!
6.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Kabir")); (a) greet (b) Kabir (c) Hello, name! (d) Hello, Kabir!
7.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(3));
8.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(30, 2));
9.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(0));
10.🧰 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(7) + fee(6));
11.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(31));
12.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Kabir")); (a) Welcome, name! (b) Kabir (c) Welcome, Kabir! (d) greet
13.🧰 In function tip(bill), what is bill? (a) a parameter (b) an event (c) a loop (d) a screen
14.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(6));
15.🧰 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(6) + fee(1));
16.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(0));
17.🧰 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(7) + fee(11));
18.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Meera")); (a) Welcome, Meera! (b) Meera (c) Welcome, name! (d) greet
19.🧰 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(10) + fee(3));
20.🧰 Why write a function? (a) to make code longer (b) to hide errors (c) to reuse code (d) to slow the app
21.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Riya")); (a) greet (b) Riya (c) Well done, Riya! (d) Well done, name!
22.🧰 A museum app works out the entry fee. What number does this code show?
function fee(age) {
  if (age < 5) {
    return 0;
  }
  return 40;
}
show(fee(3) + fee(8));
23.🧰 How do you run (call) a function called greet? (a) greet[] (b) run greet (c) #greet (d) greet()
24.🧰 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));
25.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Zoya")); (a) Hello, name! (b) greet (c) Hello, Zoya! (d) Zoya
26.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(55, 5));
27.🧰 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(3) + fee(7));
28.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(25, 6));
29.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(3));
30.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(5));
31.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(7));
32.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(3));
33.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(29));
34.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(90, 6));
35.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(36));
36.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Zoya")); (a) Zoya (b) greet (c) Well done, name! (d) Well done, Zoya!
37.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(1));
38.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(20, 4));
39.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(4));
40.🧰 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(8));

Answer key

32
60
120
a named block of code
Hi, Zoya!
Hello, Kabir!
6
60
50
100
93
Welcome, Kabir!
a parameter
18
50
40
40
Welcome, Meera!
30
to reuse code
Well done, Riya!
40
greet()
60
Hello, Zoya!
275
20
150
60
15
21
9
87
540
108
Well done, Zoya!
30
80
8
60

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