App Dev Worksheet: Functions

App development lesson 20: Functions · Set 166 · 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 does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Zoya")); (a) Welcome, Zoya! (b) Zoya (c) greet (d) Welcome, name!
2.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(20, 4));
3.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(10, 5));
4.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Aman")); (a) greet (b) Welcome, name! (c) Aman (d) Welcome, Aman!
5.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(10, 4));
6.🧰 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(7) + fee(8));
7.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(17));
8.🧰 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(6) + fee(8));
9.🧰 Why write a function? (a) to reuse code (b) to slow the app (c) to hide errors (d) to make code longer
10.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(35));
11.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(100, 3));
12.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(100, 2));
13.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(21));
14.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(3));
15.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(4));
16.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(15, 2));
17.🧰 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!
18.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(1));
19.🧰 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(8) + fee(10));
20.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(0));
21.🧰 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(2) + fee(9));
22.🧰 What is a function? (a) a screen size (b) a type of phone (c) a named block of code (d) a list of colours
23.🧰 What does return do in a function? (a) repeats the code (b) closes the screen (c) sends back a value (d) deletes the app
24.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(7));
25.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(8));
26.🧰 How do you run (call) a function called greet? (a) greet[] (b) greet() (c) #greet (d) run greet
27.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(3));
28.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(10, 6));
29.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Meera")); (a) Hello, name! (b) greet (c) Hello, Meera! (d) Meera
30.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(75, 3));
31.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Arjun")); (a) Welcome, Arjun! (b) Arjun (c) Welcome, name! (d) greet
32.🧰 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(9) + fee(6));
33.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(60, 2));
34.🧰 What does this code show?
function greet(name) {
return "Hi, " + name + "!";
}
show(greet("Kabir")); (a) greet (b) Kabir (c) Hi, name! (d) Hi, Kabir!
35.🧰 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(7));
36.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(2));
37.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(40));
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(5) + fee(3));
39.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(38));
40.🧰 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(4));

Answer key

Welcome, Zoya!
80
50
Welcome, Aman!
40
120
51
120
to reuse code
105
300
200
42
60
100
30
Well done, Riya!
50
60
60
30
a named block of code
sends back a value
21
16
greet()
6
60
Hello, Meera!
225
Welcome, Arjun!
120
120
Hi, Kabir!
50
60
120
30
76
20

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