← Functions lesson New set →

App Dev Worksheet: Functions

App development lesson 20: Functions · Set 735 · 40 questions
TalentJR

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. 1.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 4));
  2. 2.🧰 What does return do in a function? (a) deletes the app (b) closes the screen (c) repeats the code (d) sends back a value
  3. 3.🧰 How do you run (call) a function called greet? (a) #greet (b) greet() (c) greet[] (d) run greet
  4. 4.🧰 In function tip(bill), what is bill? (a) a screen (b) a loop (c) an event (d) a parameter
  5. 5.🧰 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(11));
  6. 6.🧰 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(4) + fee(12));
  7. 7.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(3));
  8. 8.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 3));
  9. 9.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(90, 4));
  10. 10.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hi, name! (b) Hi, Kabir! (c) greet (d) Kabir
  11. 11.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(1));
  12. 12.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(75, 2));
  13. 13.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Well done, Zoya! (c) Well done, name! (d) Zoya
  14. 14.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 6));
  15. 15.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir"));     (a) Well done, name! (b) Kabir (c) greet (d) Well done, Kabir!
  16. 16.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 3));
  17. 17.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Riya (b) Well done, name! (c) Well done, Riya! (d) greet
  18. 18.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(34));
  19. 19.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir"));     (a) Kabir (b) Welcome, name! (c) Welcome, Kabir! (d) greet
  20. 20.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(18));
  21. 21.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(28));
  22. 22.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(0));
  23. 23.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(3));
  24. 24.🧰 Why write a function? (a) to make code longer (b) to hide errors (c) to reuse code (d) to slow the app
  25. 25.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(37));
  26. 26.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 2));
  27. 27.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(35));
  28. 28.🧰 What is a function? (a) a type of phone (b) a list of colours (c) a named block of code (d) a screen size
  29. 29.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Hello, name! (c) Hello, Zoya! (d) Zoya
  30. 30.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(8));
  31. 31.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Meera"));     (a) greet (b) Well done, name! (c) Well done, Meera! (d) Meera
  32. 32.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Meera"));     (a) Welcome, name! (b) Meera (c) greet (d) Welcome, Meera!
  33. 33.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman"));     (a) Hi, Aman! (b) Aman (c) greet (d) Hi, name!
  34. 34.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(40));
  35. 35.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Meera"));     (a) Meera (b) Hi, name! (c) greet (d) Hi, Meera!
  36. 36.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Riya"));     (a) Riya (b) Welcome, name! (c) greet (d) Welcome, Riya!
  37. 37.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(2));
  38. 38.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(0));
  39. 39.🧰 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(2));
  40. 40.🧰 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(1));

Answer key

  1. 380
  2. sends back a value
  3. greet()
  4. a parameter
  5. 30
  6. 20
  7. 50
  8. 105
  9. 360
  10. Hi, Kabir!
  11. 30
  12. 150
  13. Well done, Zoya!
  14. 390
  15. Well done, Kabir!
  16. 45
  17. Well done, Riya!
  18. 102
  19. Welcome, Kabir!
  20. 36
  21. 56
  22. 60
  23. 9
  24. to reuse code
  25. 74
  26. 130
  27. 105
  28. a named block of code
  29. Hello, Zoya!
  30. 24
  31. Well done, Meera!
  32. Welcome, Meera!
  33. Hi, Aman!
  34. 120
  35. Hi, Meera!
  36. Welcome, Riya!
  37. 70
  38. 50
  39. 0
  40. 60

Free app development lessons, practice and worksheets at talentjr.in/app-development-for-students