App Dev Worksheet: Functions

App development lesson 20: Functions · Set 11 · 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 does return do in a function? (a) closes the screen (b) repeats the code (c) sends back a value (d) deletes the app
2.🧰 How do you run (call) a function called greet? (a) greet() (b) run greet (c) #greet (d) greet[]
3.🧰 Why write a function? (a) to reuse code (b) to slow the app (c) to hide errors (d) to make code longer
4.🧰 In function tip(bill), what is bill? (a) a parameter (b) a loop (c) a screen (d) an event
5.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Meera")); (a) Meera (b) greet (c) Hello, name! (d) Hello, Meera!
6.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(90, 3));
7.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(3));
8.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(5));
9.🧰 What is a function? (a) a named block of code (b) a type of phone (c) a list of colours (d) a screen size
10.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(1));
11.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(90, 4));
12.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(13));
13.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Arjun")); (a) Arjun (b) greet (c) Hello, name! (d) Hello, Arjun!
14.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Zoya")); (a) Zoya (b) greet (c) Well done, Zoya! (d) Well done, name!
15.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(95, 5));
16.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(10));
17.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(95, 2));
18.🧰 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(10) + fee(12));
19.🧰 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(2));
20.🧰 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(2) + fee(7));
21.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Kabir")); (a) greet (b) Well done, name! (c) Kabir (d) Well done, Kabir!
22.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(15, 2));
23.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(50, 2));
24.🧰 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(9) + fee(3));
25.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(5));
26.🧰 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(7) + fee(3));
27.🧰 What does this code show?
function greet(name) {
return "Hi, " + name + "!";
}
show(greet("Arjun")); (a) Arjun (b) Hi, name! (c) greet (d) Hi, Arjun!
28.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(20, 6));
29.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(24));
30.🧰 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(1));
31.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(28));
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(8) + fee(2));
33.🧰 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(6));
34.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(4));
35.🧰 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(1));
36.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(80, 5));
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 total(price, qty) {
return price * qty;
}
show(total(25, 2));
39.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Kabir")); (a) greet (b) Hello, name! (c) Kabir (d) Hello, Kabir!
40.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Arjun")); (a) Well done, name! (b) Arjun (c) greet (d) Well done, Arjun!

Answer key

sends back a value
greet()
to reuse code
a parameter
Hello, Meera!
270
60
80
a named block of code
40
360
39
Hello, Arjun!
Well done, Zoya!
475
30
190
40
50
30
Well done, Kabir!
30
100
40
90
40
Hi, Arjun!
120
72
0
56
60
80
90
20
400
80
50
Hello, Kabir!
Well done, Arjun!

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