App Dev Worksheet: Functions

App development lesson 20: Functions · Set 483 · 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(25, 3));
2.🧰 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(4) + fee(1));
3.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(15));
4.🧰 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!
5.🧰 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(6) + fee(11));
6.🧰 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(9));
7.🧰 How do you run (call) a function called greet? (a) greet[] (b) run greet (c) greet() (d) #greet
8.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(37));
9.🧰 What does return do in a function? (a) closes the screen (b) deletes the app (c) repeats the code (d) sends back a value
10.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(14));
11.🧰 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(10) + fee(3));
12.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(1));
13.🧰 In function tip(bill), what is bill? (a) a loop (b) an event (c) a screen (d) a parameter
14.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Arjun")); (a) Welcome, name! (b) Arjun (c) greet (d) Welcome, Arjun!
15.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(5));
16.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(15, 3));
17.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(0));
18.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(0));
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(7) + fee(6));
20.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(6));
21.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(0));
22.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(75, 6));
23.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Kabir")); (a) Well done, name! (b) Well done, Kabir! (c) greet (d) Kabir
24.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Riya")); (a) greet (b) Riya (c) Hello, Riya! (d) Hello, name!
25.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(45, 3));
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(12) + fee(5));
27.🧰 Why write a function? (a) to hide errors (b) to make code longer (c) to slow the app (d) to reuse code
28.🧰 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(3) + fee(11));
29.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(2));
30.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Kabir")); (a) Hello, Kabir! (b) Kabir (c) greet (d) Hello, name!
31.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(1));
32.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(3));
33.🧰 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(4));
34.🧰 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(3) + fee(1));
35.🧰 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(4) + fee(6));
36.🧰 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(11));
37.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(14));
38.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(2));
39.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(2));
40.🧰 What is a function? (a) a type of phone (b) a screen size (c) a list of colours (d) a named block of code

Answer key

75
0
30
Well done, Arjun!
60
100
greet()
74
sends back a value
28
60
70
a parameter
Welcome, Arjun!
100
45
40
50
100
18
60
450
Well done, Kabir!
Hello, Riya!
135
40
to reuse code
20
80
Hello, Kabir!
50
90
50
0
50
30
42
40
50
a named block of code

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