App Dev Worksheet: Functions

App development lesson 20: Functions · Set 354 · 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.🧰 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(5) + fee(8));
2.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(4));
3.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(90, 3));
4.🧰 What does return do in a function? (a) closes the screen (b) repeats the code (c) deletes the app (d) sends back a value
5.🧰 How do you run (call) a function called greet? (a) run greet (b) #greet (c) greet() (d) greet[]
6.🧰 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(5) + fee(12));
7.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(0));
8.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(20, 2));
9.🧰 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(3));
10.🧰 In function tip(bill), what is bill? (a) an event (b) a loop (c) a screen (d) a parameter
11.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(4));
12.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(34));
13.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Aman")); (a) Aman (b) Well done, name! (c) Well done, Aman! (d) greet
14.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(60, 4));
15.🧰 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(7) + fee(8));
16.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(50, 3));
17.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(8));
18.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(38));
19.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(10));
20.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(1));
21.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(40));
22.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(32));
23.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(5));
24.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(5));
25.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Arjun")); (a) Hello, name! (b) Hello, Arjun! (c) Arjun (d) greet
26.🧰 Why write a function? (a) to make code longer (b) to hide errors (c) to slow the app (d) to reuse code
27.🧰 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(7) + fee(4));
28.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Meera")); (a) greet (b) Meera (c) Well done, Meera! (d) Well done, name!
29.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(26));
30.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(2));
31.🧰 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(6) + fee(4));
32.🧰 What is a function? (a) a screen size (b) a list of colours (c) a named block of code (d) a type of phone
33.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Aman")); (a) Hello, Aman! (b) Aman (c) Hello, name! (d) greet
34.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(100, 6));
35.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Zoya")); (a) Zoya (b) greet (c) Hello, Zoya! (d) Hello, name!
36.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(20, 3));
37.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Meera")); (a) greet (b) Hello, name! (c) Hello, Meera! (d) Meera
38.🧰 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(11) + fee(3));
39.🧰 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(2) + fee(8));
40.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(4));

Answer key

40
12
270
sends back a value
greet()
40
30
40
0
a parameter
80
102
Well done, Aman!
240
120
150
24
76
20
40
80
96
80
100
Hello, Arjun!
to reuse code
60
Well done, Meera!
52
50
60
a named block of code
Hello, Aman!
600
Hello, Zoya!
60
Hello, Meera!
50
20
90

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