App Dev Worksheet: Functions

App development lesson 20: Functions · Set 183 · 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.🧰 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(11));
2.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(1));
3.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(4));
4.🧰 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(12));
5.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(5));
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(2) + fee(8));
7.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(0));
8.🧰 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(10));
9.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(9));
10.🧰 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(4));
11.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Meera")); (a) Hello, name! (b) greet (c) Hello, Meera! (d) Meera
12.🧰 What is a function? (a) a type of phone (b) a list of colours (c) a screen size (d) a named block of code
13.🧰 Why write a function? (a) to reuse code (b) to hide errors (c) to slow the app (d) to make code longer
14.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(95, 4));
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(7) + fee(1));
16.🧰 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(6) + fee(1));
17.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(4));
18.🧰 What does this code show?
function greet(name) {
return "Hi, " + name + "!";
}
show(greet("Zoya")); (a) Hi, name! (b) Zoya (c) Hi, Zoya! (d) greet
19.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(0));
20.🧰 What does return do in a function? (a) repeats the code (b) deletes the app (c) closes the screen (d) sends back a value
21.🧰 What does this code show?
function greet(name) {
return "Hi, " + name + "!";
}
show(greet("Riya")); (a) Hi, name! (b) Riya (c) greet (d) Hi, Riya!
22.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(5));
23.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Kabir")); (a) Kabir (b) Well done, name! (c) Well done, Kabir! (d) greet
24.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(8));
25.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(24));
26.🧰 In function tip(bill), what is bill? (a) a loop (b) an event (c) a screen (d) a parameter
27.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(20));
28.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(18));
29.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Riya")); (a) Hello, name! (b) greet (c) Riya (d) Hello, Riya!
30.🧰 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(5) + fee(4));
31.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(5));
32.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(28));
33.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(11));
34.🧰 How do you run (call) a function called greet? (a) greet[] (b) run greet (c) greet() (d) #greet
35.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(40, 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(11) + fee(10));
37.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(2));
38.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(5));
39.🧰 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(10) + fee(5));
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(10) + fee(9));

Answer key

50
60
60
120
70
50
60
40
27
0
Hello, Meera!
a named block of code
to reuse code
380
30
50
70
Hi, Zoya!
30
sends back a value
Hi, Riya!
80
Well done, Kabir!
16
72
a parameter
40
36
Hello, Riya!
20
90
56
33
greet()
240
60
40
110
100
80

Free app development lessons, practice and worksheets at talentjr.in/app-development-for-students