App Dev Worksheet: Functions

App development lesson 20: Functions · Set 652 · 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(17));
2.🧰 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(1) + fee(2));
3.🧰 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(11) + fee(8));
4.🧰 What does return do in a function? (a) closes the screen (b) sends back a value (c) repeats the code (d) deletes the app
5.🧰 What is a function? (a) a screen size (b) a list of colours (c) a type of phone (d) a named block of code
6.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(0));
7.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(30, 3));
8.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(21));
9.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(4));
10.🧰 How do you run (call) a function called greet? (a) #greet (b) run greet (c) greet[] (d) greet()
11.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(5));
12.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(3));
13.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(95, 2));
14.🧰 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(9));
15.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(0));
16.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Aman")); (a) Well done, name! (b) greet (c) Aman (d) Well done, Aman!
17.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Meera")); (a) Well done, name! (b) Meera (c) Well done, Meera! (d) greet
18.🧰 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(1) + fee(3));
19.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(27));
20.🧰 Why write a function? (a) to reuse code (b) to slow the app (c) to hide errors (d) to make code longer
21.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Riya")); (a) Hello, name! (b) Riya (c) Hello, Riya! (d) greet
22.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(16));
23.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(8));
24.🧰 What does this code show?
function greet(name) {
return "Hi, " + name + "!";
}
show(greet("Arjun")); (a) Hi, Arjun! (b) greet (c) Hi, name! (d) Arjun
25.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(2));
26.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(4));
27.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(0));
28.🧰 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(4) + fee(5));
29.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(18));
30.🧰 In function tip(bill), what is bill? (a) a parameter (b) a screen (c) an event (d) a loop
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(1) + fee(11));
32.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Aman")); (a) Welcome, name! (b) greet (c) Welcome, Aman! (d) Aman
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(3) + fee(4));
34.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Kabir")); (a) Hello, name! (b) greet (c) Hello, Kabir! (d) Kabir
35.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(30, 6));
36.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Zoya")); (a) Zoya (b) Hello, Zoya! (c) Hello, name! (d) greet
37.🧰 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(2));
38.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(0));
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(5) + fee(3));
40.🧰 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(2));

Answer key

34
0
80
sends back a value
a named block of code
30
90
42
8
greet()
70
80
190
80
20
Well done, Aman!
Well done, Meera!
0
54
to reuse code
Hello, Riya!
48
16
Hi, Arjun!
60
90
40
40
36
a parameter
40
Welcome, Aman!
0
Hello, Kabir!
180
Hello, Zoya!
40
60
60
40

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