App Dev Worksheet: Functions

App development lesson 20: Functions · Set 909 · 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 is a function? (a) a type of phone (b) a list of colours (c) a named block of code (d) a screen size
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(10) + fee(9));
3.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(85, 3));
4.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(5));
5.🧰 Why write a function? (a) to slow the app (b) to make code longer (c) to reuse code (d) to hide errors
6.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(3));
7.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Aman")); (a) Well done, name! (b) greet (c) Well done, Aman! (d) Aman
8.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(12));
9.🧰 What does return do in a function? (a) closes the screen (b) sends back a value (c) deletes the app (d) repeats the code
10.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(2));
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(5) + 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 30;
}
show(fee(8) + fee(12));
13.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(10, 6));
14.🧰 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(2));
15.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(2));
16.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(9));
17.🧰 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(5));
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(9) + fee(1));
19.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(8));
20.🧰 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(5) + fee(10));
21.🧰 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(11) + fee(1));
22.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(30, 2));
23.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(90, 4));
24.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Meera")); (a) greet (b) Hello, Meera! (c) Hello, name! (d) Meera
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(9) + fee(3));
26.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Zoya")); (a) Hello, Zoya! (b) greet (c) Hello, name! (d) Zoya
27.🧰 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(5) + fee(8));
28.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Kabir")); (a) Kabir (b) greet (c) Hello, Kabir! (d) Hello, name!
29.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(7));
30.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(1));
31.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(2));
32.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(29));
33.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(28));
34.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(0));
35.🧰 In function tip(bill), what is bill? (a) a screen (b) a loop (c) a parameter (d) an event
36.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(35));
37.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(15, 6));
38.🧰 How do you run (call) a function called greet? (a) #greet (b) greet[] (c) greet() (d) run greet
39.🧰 What does this code show?
function greet(name) {
return "Hi, " + name + "!";
}
show(greet("Riya")); (a) Riya (b) Hi, name! (c) greet (d) Hi, Riya!
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(7) + fee(8));

Answer key

a named block of code
40
255
80
to reuse code
90
Well done, Aman!
36
sends back a value
70
50
60
60
0
80
27
80
20
24
80
50
60
360
Hello, Meera!
50
Hello, Zoya!
80
Hello, Kabir!
14
40
50
58
84
40
a parameter
70
90
greet()
Hi, Riya!
80

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