App Dev Worksheet: Functions

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

Answer key

36
72
Welcome, Arjun!
60
120
80
80
to reuse code
Hello, Meera!
40
70
150
sends back a value
12
a named block of code
50
a parameter
greet()
120
46
40
80
30
120
475
20
120
60
60
0
180
0
69
28
200
120
Well done, Arjun!
190
0
Hello, Zoya!

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