App Dev Worksheet: Functions

App development lesson 20: Functions · Set 482 · 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(10, 3));
2.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(34));
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(4) + fee(4));
4.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Aman")); (a) Welcome, name! (b) Aman (c) greet (d) Welcome, Aman!
5.🧰 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(11) + fee(4));
6.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(31));
7.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(25, 4));
8.🧰 Why write a function? (a) to hide errors (b) to slow the app (c) to make code longer (d) to reuse code
9.🧰 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));
10.🧰 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(1));
11.🧰 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(9));
12.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(0));
13.🧰 What does this code show?
function greet(name) {
return "Hi, " + name + "!";
}
show(greet("Kabir")); (a) Hi, name! (b) greet (c) Kabir (d) Hi, Kabir!
14.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Arjun")); (a) Arjun (b) greet (c) Welcome, name! (d) Welcome, Arjun!
15.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(70, 2));
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(12) + fee(6));
17.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(35, 3));
18.🧰 In function tip(bill), what is bill? (a) an event (b) a screen (c) a loop (d) a parameter
19.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(29));
20.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(26));
21.🧰 What is a function? (a) a named block of code (b) a list of colours (c) a type of phone (d) a screen size
22.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(5));
23.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(60, 2));
24.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Meera")); (a) Meera (b) Welcome, name! (c) Welcome, Meera! (d) greet
25.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(8));
26.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Riya")); (a) greet (b) Hello, name! (c) Hello, Riya! (d) Riya
27.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(33));
28.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(45, 2));
29.🧰 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(12) + fee(10));
30.🧰 What does return do in a function? (a) sends back a value (b) repeats the code (c) closes the screen (d) deletes the app
31.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Zoya")); (a) Hello, name! (b) Zoya (c) Hello, Zoya! (d) greet
32.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(15));
33.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(12));
34.🧰 How do you run (call) a function called greet? (a) greet() (b) greet[] (c) #greet (d) run 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(12) + fee(10));
36.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(60, 5));
37.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(21));
38.🧰 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(9) + fee(3));
39.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(0));
40.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(5));

Answer key

30
68
0
Welcome, Aman!
20
93
100
to reuse code
40
20
30
50
Hi, Kabir!
Welcome, Arjun!
140
80
105
a parameter
58
78
a named block of code
110
120
Welcome, Meera!
16
Hello, Riya!
66
90
120
sends back a value
Hello, Zoya!
30
24
greet()
80
300
42
30
20
15

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