App Dev Worksheet: Functions

App development lesson 20: Functions · Set 535 · 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("Meera")); (a) Welcome, name! (b) Welcome, Meera! (c) greet (d) Meera
2.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(15, 6));
3.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(13));
4.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(95, 4));
5.🧰 What does this code show?
function greet(name) {
return "Hi, " + name + "!";
}
show(greet("Zoya")); (a) Zoya (b) Hi, Zoya! (c) Hi, name! (d) greet
6.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(7));
7.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Riya")); (a) Well done, name! (b) greet (c) Riya (d) Well done, Riya!
8.🧰 What is a function? (a) a type of phone (b) a screen size (c) a list of colours (d) a named block of code
9.🧰 What does return do in a function? (a) sends back a value (b) closes the screen (c) repeats the code (d) deletes the app
10.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(3));
11.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(45, 6));
12.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(35, 2));
13.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(75, 4));
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 points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(3));
16.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Riya")); (a) Riya (b) greet (c) Welcome, Riya! (d) Welcome, name!
17.🧰 In function tip(bill), what is bill? (a) an event (b) a screen (c) a loop (d) a parameter
18.🧰 How do you run (call) a function called greet? (a) greet[] (b) run greet (c) greet() (d) #greet
19.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(40, 6));
20.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Arjun")); (a) Arjun (b) greet (c) Well done, name! (d) Well done, Arjun!
21.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Kabir")); (a) Well done, Kabir! (b) Well done, name! (c) greet (d) Kabir
22.🧰 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(3));
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(2));
24.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(22));
25.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(60, 4));
26.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(5));
27.🧰 Why write a function? (a) to hide errors (b) to slow the app (c) to reuse code (d) to make code longer
28.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(40, 4));
29.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(95, 3));
30.🧰 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));
31.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(34));
32.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(27));
33.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Arjun")); (a) Welcome, name! (b) Arjun (c) greet (d) Welcome, Arjun!
34.🧰 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(11) + fee(11));
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(2) + fee(9));
36.🧰 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(8) + fee(1));
37.🧰 What does this code show?
function greet(name) {
return "Hi, " + name + "!";
}
show(greet("Meera")); (a) Hi, name! (b) greet (c) Hi, Meera! (d) Meera
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(3) + fee(6));
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 double(n) {
return n * 2;
}
show(double(18));

Answer key

Welcome, Meera!
90
26
380
Hi, Zoya!
14
Well done, Riya!
a named block of code
sends back a value
70
270
70
300
60
80
Welcome, Riya!
a parameter
greet()
240
Well done, Arjun!
Well done, Kabir!
50
0
44
240
110
to reuse code
160
285
50
102
54
Welcome, Arjun!
80
60
20
Hi, Meera!
30
20
36

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