App Dev Worksheet: Functions

App development lesson 20: Functions · Set 947 · 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(80, 2));
2.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(19));
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(3) + fee(7));
4.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(4));
5.🧰 In function tip(bill), what is bill? (a) an event (b) a loop (c) a screen (d) a parameter
6.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(35));
7.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(1));
8.🧰 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(2) + fee(1));
9.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Zoya")); (a) greet (b) Zoya (c) Well done, Zoya! (d) Well done, name!
10.🧰 What does return do in a function? (a) closes the screen (b) repeats the code (c) sends back a value (d) deletes the app
11.🧰 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(7) + fee(7));
12.🧰 Why write a function? (a) to make code longer (b) to slow the app (c) to reuse code (d) to hide errors
13.🧰 What is a function? (a) a named block of code (b) a type of phone (c) a screen size (d) a list of colours
14.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Kabir")); (a) Kabir (b) Hello, Kabir! (c) greet (d) Hello, name!
15.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(95, 6));
16.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(65, 2));
17.🧰 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
18.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Arjun")); (a) Arjun (b) Welcome, Arjun! (c) Welcome, name! (d) greet
19.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(1));
20.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(0));
21.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(6));
22.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(0));
23.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(5));
24.🧰 How do you run (call) a function called greet? (a) greet() (b) greet[] (c) #greet (d) run greet
25.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(15, 4));
26.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(65, 6));
27.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(0));
28.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(50, 5));
29.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Riya")); (a) Riya (b) Well done, name! (c) Well done, Riya! (d) greet
30.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(5));
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(10) + fee(3));
32.🧰 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(8));
33.🧰 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(5) + fee(3));
34.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Meera")); (a) Welcome, Meera! (b) Welcome, name! (c) Meera (d) greet
35.🧰 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(3));
36.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(4));
37.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(0));
38.🧰 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));
39.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(1));
40.🧰 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(12) + fee(1));

Answer key

160
57
40
8
a parameter
70
40
0
Well done, Zoya!
sends back a value
40
to reuse code
a named block of code
Hello, Kabir!
570
130
Well done, Kabir!
Welcome, Arjun!
60
30
18
60
15
greet()
60
390
20
250
Well done, Riya!
10
40
40
30
Welcome, Meera!
0
60
40
40
30
30

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