App Dev Worksheet: Functions

App development lesson 20: Functions · Set 606 · 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 total(price, qty) {
return price * qty;
}
show(total(90, 4));
2.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(25, 2));
3.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(36));
4.🧰 How do you run (call) a function called greet? (a) run greet (b) #greet (c) greet() (d) greet[]
5.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(6));
6.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Zoya")); (a) Welcome, name! (b) Welcome, Zoya! (c) Zoya (d) greet
7.🧰 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(1));
8.🧰 In function tip(bill), what is bill? (a) a parameter (b) an event (c) a screen (d) a loop
9.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Arjun")); (a) Arjun (b) Hello, name! (c) Hello, Arjun! (d) greet
10.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(7));
11.🧰 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(3));
12.🧰 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(1) + fee(9));
13.🧰 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(8) + fee(5));
14.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Kabir")); (a) Kabir (b) Well done, Kabir! (c) greet (d) Well done, name!
15.🧰 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(10));
16.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(34));
17.🧰 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(11) + fee(4));
18.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(3));
19.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(0));
20.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Meera")); (a) Hello, name! (b) Meera (c) Hello, Meera! (d) greet
21.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Aman")); (a) Welcome, Aman! (b) Aman (c) greet (d) Welcome, name!
22.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(9));
23.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(1));
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(8) + fee(5));
25.🧰 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(1) + fee(1));
26.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(2));
27.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(8));
28.🧰 What is a function? (a) a type of phone (b) a list of colours (c) a screen size (d) a named block of code
29.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(80, 5));
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(12) + fee(1));
31.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(4));
32.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(50, 3));
33.🧰 What does return do in a function? (a) deletes the app (b) closes the screen (c) sends back a value (d) repeats the code
34.🧰 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(7) + fee(2));
35.🧰 Why write a function? (a) to slow the app (b) to make code longer (c) to hide errors (d) to reuse code
36.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(0));
37.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(23));
38.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(11));
39.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(2));
40.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(20, 6));

Answer key

360
50
108
greet()
12
Welcome, Zoya!
0
a parameter
Hello, Arjun!
21
0
50
100
Well done, Kabir!
30
68
30
60
40
Hello, Meera!
Welcome, Aman!
27
30
120
0
40
16
a named block of code
400
50
60
150
sends back a value
30
to reuse code
20
69
33
70
120

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