App Dev Worksheet: Functions

App development lesson 20: Functions · Set 95 · 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 50;
}
show(fee(12) + fee(7));
2.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(0));
3.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Meera")); (a) Meera (b) Welcome, Meera! (c) greet (d) Welcome, name!
4.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(5));
5.🧰 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(9) + fee(3));
6.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(15));
7.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(10, 4));
8.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(15, 3));
9.🧰 How do you run (call) a function called greet? (a) #greet (b) greet() (c) run greet (d) greet[]
10.🧰 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(8) + fee(3));
11.🧰 What is a function? (a) a screen size (b) a type of phone (c) a named block of code (d) a list of colours
12.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(14));
13.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(34));
14.🧰 What does return do in a function? (a) repeats the code (b) sends back a value (c) deletes the app (d) closes the screen
15.🧰 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(10) + fee(10));
16.🧰 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(1) + fee(10));
17.🧰 Why write a function? (a) to slow the app (b) to hide errors (c) to reuse code (d) to make code longer
18.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(4));
19.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(40, 2));
20.🧰 In function tip(bill), what is bill? (a) a screen (b) an event (c) a parameter (d) a loop
21.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(1));
22.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Kabir")); (a) Kabir (b) greet (c) Well done, Kabir! (d) Well done, name!
23.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(60, 6));
24.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(1));
25.🧰 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(3) + fee(10));
26.🧰 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(8) + fee(10));
27.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(3));
28.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(35, 2));
29.🧰 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(6));
30.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(32));
31.🧰 What does this code show?
function greet(name) {
return "Hi, " + name + "!";
}
show(greet("Arjun")); (a) Arjun (b) Hi, Arjun! (c) Hi, name! (d) greet
32.🧰 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(12));
33.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Arjun")); (a) Well done, name! (b) greet (c) Well done, Arjun! (d) Arjun
34.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(45, 2));
35.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(39));
36.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(37));
37.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(2));
38.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(2));
39.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Riya")); (a) Well done, name! (b) greet (c) Riya (d) Well done, Riya!
40.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Riya")); (a) Hello, name! (b) greet (c) Hello, Riya! (d) Riya

Answer key

100
40
Welcome, Meera!
70
30
30
40
45
greet()
40
a named block of code
28
68
sends back a value
80
60
to reuse code
90
80
a parameter
40
Well done, Kabir!
360
70
30
60
50
70
20
64
Hi, Arjun!
120
Well done, Arjun!
90
117
111
80
70
Well done, Riya!
Hello, Riya!

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