App Dev Worksheet: Functions

App development lesson 20: Functions · Set 745 · 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 double(n) {
return n * 2;
}
show(double(3));
2.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Arjun")); (a) greet (b) Welcome, Arjun! (c) Arjun (d) Welcome, name!
3.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(70, 2));
4.🧰 Why write a function? (a) to slow the app (b) to reuse code (c) to hide errors (d) to make code longer
5.🧰 In function tip(bill), what is bill? (a) a loop (b) a screen (c) an event (d) a parameter
6.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(2));
7.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(33));
8.🧰 How do you run (call) a function called greet? (a) run greet (b) greet[] (c) #greet (d) greet()
9.🧰 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(12));
10.🧰 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
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(1) + fee(7));
12.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(15, 6));
13.🧰 What does return do in a function? (a) sends back a value (b) repeats the code (c) closes the screen (d) deletes the app
14.🧰 What is a function? (a) a list of colours (b) a type of phone (c) a screen size (d) a named block of code
15.🧰 What does this code show?
function greet(name) {
return "Hi, " + name + "!";
}
show(greet("Kabir")); (a) greet (b) Kabir (c) Hi, Kabir! (d) Hi, name!
16.🧰 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(7) + fee(1));
17.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(2));
18.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(17));
19.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(3) + points(5));
20.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(20, 2));
21.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(4) + points(5));
22.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(10, 5));
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(5) + fee(4));
24.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(15, 4));
25.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(18));
26.🧰 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(5));
27.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(1));
28.🧰 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(8) + fee(9));
29.🧰 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(1) + fee(9));
30.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Riya")); (a) Hello, Riya! (b) Hello, name! (c) Riya (d) greet
31.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(2));
32.🧰 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(5) + fee(2));
33.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(1));
34.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(55, 3));
35.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Zoya")); (a) Hello, Zoya! (b) greet (c) Hello, name! (d) Zoya
36.🧰 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(10) + fee(3));
37.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(0));
38.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Arjun")); (a) Arjun (b) Hello, name! (c) Hello, Arjun! (d) greet
39.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(35));
40.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(70, 3));

Answer key

6
Welcome, Arjun!
140
to reuse code
a parameter
70
66
greet()
60
Well done, Kabir!
30
90
sends back a value
a named block of code
Hi, Kabir!
20
50
51
90
40
100
50
50
60
54
120
70
100
30
Hello, Riya!
40
20
40
165
Hello, Zoya!
60
60
Hello, Arjun!
70
210

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