App Dev Worksheet: Functions

App development lesson 20: Functions · Set 63 · 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 triple(n) {
return n * 3;
}
show(triple(3));
2.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Riya")); (a) Welcome, name! (b) greet (c) Welcome, Riya! (d) Riya
3.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(5));
4.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(9));
5.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(3));
6.🧰 What does this code show?
function greet(name) {
return "Hi, " + name + "!";
}
show(greet("Zoya")); (a) greet (b) Zoya (c) Hi, Zoya! (d) Hi, name!
7.🧰 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(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(12) + fee(1));
9.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Arjun")); (a) Arjun (b) Hello, Arjun! (c) greet (d) Hello, name!
10.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Kabir")); (a) Kabir (b) Well done, name! (c) greet (d) Well done, Kabir!
11.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(90, 4));
12.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(30, 5));
13.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(30));
14.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(20));
15.🧰 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(8) + fee(4));
16.🧰 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(4));
17.🧰 What does this code show?
function greet(name) {
return "Hi, " + name + "!";
}
show(greet("Riya")); (a) Hi, name! (b) Hi, Riya! (c) Riya (d) greet
18.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(15, 2));
19.🧰 What is a function? (a) a type of phone (b) a named block of code (c) a list of colours (d) a screen size
20.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(38));
21.🧰 How do you run (call) a function called greet? (a) run greet (b) #greet (c) greet() (d) greet[]
22.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(11));
23.🧰 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(3) + fee(12));
24.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(35, 4));
25.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(10, 2));
26.🧰 Why write a function? (a) to make code longer (b) to hide errors (c) to slow the app (d) to reuse code
27.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(30, 4));
28.🧰 In function tip(bill), what is bill? (a) a loop (b) a screen (c) an event (d) a parameter
29.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(32));
30.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Meera")); (a) Welcome, Meera! (b) Welcome, name! (c) Meera (d) greet
31.🧰 What does this code show?
function greet(name) {
return "Hi, " + name + "!";
}
show(greet("Arjun")); (a) greet (b) Hi, name! (c) Arjun (d) Hi, Arjun!
32.🧰 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(1));
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(4) + fee(6));
34.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(4));
35.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(8));
36.🧰 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(5));
37.🧰 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(12) + fee(8));
38.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(1));
39.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(16));
40.🧰 What does return do in a function? (a) sends back a value (b) repeats the code (c) closes the screen (d) deletes the app

Answer key

9
Welcome, Riya!
70
27
50
Hi, Zoya!
60
40
Hello, Arjun!
Well done, Kabir!
360
150
60
60
60
30
Hi, Riya!
30
a named block of code
114
greet()
22
50
140
20
to reuse code
120
a parameter
96
Welcome, Meera!
Hi, Arjun!
30
30
80
16
100
100
30
48
sends back a value

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