App Dev Worksheet: Functions

App development lesson 20: Functions · Set 597 · 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 points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(0));
2.🧰 How do you run (call) a function called greet? (a) run greet (b) greet() (c) #greet (d) greet[]
3.🧰 What does return do in a function? (a) sends back a value (b) deletes the app (c) closes the screen (d) repeats the code
4.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(18));
5.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Aman")); (a) Aman (b) Welcome, name! (c) Welcome, Aman! (d) greet
6.🧰 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(6) + fee(2));
7.🧰 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(8) + fee(5));
8.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(100, 5));
9.🧰 In function tip(bill), what is bill? (a) a screen (b) a loop (c) an event (d) a parameter
10.🧰 What does this code show?
function greet(name) {
return "Hi, " + name + "!";
}
show(greet("Riya")); (a) Hi, Riya! (b) greet (c) Hi, name! (d) Riya
11.🧰 What is a function? (a) a type of phone (b) a screen size (c) a list of colours (d) a named block of code
12.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(32));
13.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(31));
14.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(1));
15.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(20, 3));
16.🧰 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(3));
17.🧰 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(2) + fee(10));
18.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(2));
19.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Kabir")); (a) Kabir (b) Welcome, Kabir! (c) Welcome, name! (d) greet
20.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(4));
21.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(2));
22.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(0));
23.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(65, 6));
24.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(38));
25.🧰 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(5));
26.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Riya")); (a) greet (b) Hello, Riya! (c) Hello, name! (d) Riya
27.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(35, 2));
28.🧰 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(2) + fee(2));
29.🧰 Why write a function? (a) to reuse code (b) to make code longer (c) to slow the app (d) to hide errors
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(9) + fee(10));
31.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(30, 2));
32.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(38));
33.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Aman")); (a) greet (b) Well done, Aman! (c) Well done, name! (d) Aman
34.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(4));
35.🧰 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(10));
36.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Meera")); (a) greet (b) Meera (c) Hello, Meera! (d) Hello, name!
37.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(80, 5));
38.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(39));
39.🧰 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(6) + fee(9));
40.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Riya")); (a) greet (b) Well done, Riya! (c) Riya (d) Well done, name!

Answer key

40
greet()
sends back a value
36
Welcome, Aman!
20
80
500
a parameter
Hi, Riya!
a named block of code
64
62
60
60
40
20
80
Welcome, Kabir!
100
60
30
390
114
80
Hello, Riya!
70
0
to reuse code
40
60
76
Well done, Aman!
8
120
Hello, Meera!
400
78
80
Well done, Riya!

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