App Dev Worksheet: Functions

App development lesson 20: Functions · Set 583 · 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 "Hi, " + name + "!";
}
show(greet("Zoya")); (a) Hi, name! (b) Hi, Zoya! (c) Zoya (d) greet
2.🧰 What does return do in a function? (a) deletes the app (b) sends back a value (c) repeats the code (d) closes the screen
3.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(17));
4.🧰 How do you run (call) a function called greet? (a) greet() (b) run greet (c) #greet (d) greet[]
5.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(55, 2));
6.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(19));
7.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(4));
8.🧰 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(7));
9.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Arjun")); (a) Welcome, name! (b) Arjun (c) Welcome, Arjun! (d) greet
10.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(15));
11.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(1));
12.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(5));
13.🧰 In function tip(bill), what is bill? (a) a loop (b) a parameter (c) an event (d) a screen
14.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(65, 2));
15.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(0));
16.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(2) + points(0));
17.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(85, 2));
18.🧰 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(4) + fee(10));
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(9) + fee(1));
20.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(35, 4));
21.🧰 What is a function? (a) a screen size (b) a list of colours (c) a type of phone (d) a named block of code
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(3) + fee(4));
23.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Kabir")); (a) greet (b) Hello, Kabir! (c) Hello, name! (d) Kabir
24.🧰 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(2));
25.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Meera")); (a) Meera (b) greet (c) Hello, Meera! (d) Hello, name!
26.🧰 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(8));
27.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(5) + points(3));
28.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(65, 6));
29.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(45, 2));
30.🧰 What does this code show?
function greet(name) {
return "Hello, " + name + "!";
}
show(greet("Aman")); (a) greet (b) Hello, Aman! (c) Hello, name! (d) Aman
31.🧰 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(4));
32.🧰 Why write a function? (a) to hide errors (b) to slow the app (c) to reuse code (d) to make code longer
33.🧰 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(5));
34.🧰 What does this code show?
function greet(name) {
return "Welcome, " + name + "!";
}
show(greet("Meera")); (a) Welcome, name! (b) Meera (c) greet (d) Welcome, Meera!
35.🧰 What number does this code show?
function triple(n) {
return n * 3;
}
show(triple(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 40;
}
show(fee(6) + fee(3));
37.🧰 What does this code show?
function greet(name) {
return "Well done, " + name + "!";
}
show(greet("Riya")); (a) Well done, Riya! (b) Riya (c) greet (d) Well done, name!
38.🧰 What number does this code show?
function total(price, qty) {
return price * qty;
}
show(total(80, 5));
39.🧰 What number does this code show?
function double(n) {
return n * 2;
}
show(double(38));
40.🧰 What number does this code show?
function points(stars) {
return stars * 10 + 5;
}
show(points(1) + points(2));

Answer key

Hi, Zoya!
sends back a value
34
greet()
110
38
60
40
Welcome, Arjun!
45
30
15
a parameter
130
20
30
170
60
30
140
a named block of code
0
Hello, Kabir!
0
Hello, Meera!
50
90
390
90
Hello, Aman!
60
to reuse code
40
Welcome, Meera!
27
40
Well done, Riya!
400
76
40

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