App Dev Worksheet: Functions

App development lesson 20: Functions · Set 646 · 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(3) + points(0));
2.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(30));
3.🧰 What is a function? (a) a list of colours (b) a named block of code (c) a type of phone (d) a screen size
4.🧰 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(9) + fee(11));
5.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Riya")); (a) Well done, Riya! (b) greet (c) Well done, name! (d) Riya
6.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(10));
7.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Meera")); (a) Well done, name! (b) greet (c) Meera (d) Well done, Meera!
8.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(5));
9.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(0));
10.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(4));
11.🧰 How do you run (call) a function called greet? (a) run greet (b) greet[] (c) greet() (d) #greet
12.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(4));
13.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(2));
14.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(15));
15.🧰 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(5));
16.🧰 What does return do in a function? (a) deletes the app (b) sends back a value (c) closes the screen (d) repeats the code
17.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Aman")); (a) greet (b) Welcome, name! (c) Welcome, Aman! (d) Aman
18.🧰 In function tip(bill), what is bill? (a) a parameter (b) a screen (c) a loop (d) an event
19.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(40, 5));
20.🧰 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(2) + fee(7));
21.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(6));
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(12) + fee(1));
23.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(35));
24.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(15, 4));
25.🧰 What does this code show?
function greet(name) {
return "Hi, " + name + "!";
}
show(greet("Riya")); (a) Hi, name! (b) Riya (c) Hi, Riya! (d) greet
26.🧰 Why write a function? (a) to slow the app (b) to hide errors (c) to reuse code (d) to make code longer
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(12));
28.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(0));
29.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(70, 2));
30.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(3));
31.🧰 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(2) + fee(3));
32.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(13));
33.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(1));
34.🧰 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(4) + fee(11));
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 "Welcome, " + name + "!";
}
show(greet("Arjun")); (a) Welcome, Arjun! (b) Welcome, name! (c) greet (d) Arjun
37.🧰 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(4));
38.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(7));
39.🧰 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(10) + fee(1));
40.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(15, 5));

Answer key

40
90
a named block of code
100
Well done, Riya!
30
Well done, Meera!
110
50
100
greet()
70
80
45
20
sends back a value
Welcome, Aman!
a parameter
200
50
18
40
105
60
Hi, Riya!
to reuse code
20
30
140
6
0
39
70
20
108
Welcome, Arjun!
30
14
60
75

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