← Functions lesson New set →

App Dev Worksheet: Functions

App development lesson 20: Functions · Set 582 · 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 does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Riya"));     (a) greet (b) Welcome, name! (c) Welcome, Riya! (d) Riya
  2. 2.🧰 What does return do in a function? (a) sends back a value (b) closes the screen (c) deletes the app (d) repeats the code
  3. 3.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 3));
  4. 4.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(11));
  5. 5.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Well done, Riya! (b) greet (c) Riya (d) Well done, name!
  6. 6.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 6));
  7. 7.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(1));
  8. 8.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(6));
  9. 9.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(38));
  10. 10.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Aman (c) Well done, name! (d) Well done, Aman!
  11. 11.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 3));
  12. 12.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 2));
  13. 13.🧰 Why write a function? (a) to hide errors (b) to make code longer (c) to slow the app (d) to reuse code
  14. 14.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman"));     (a) Welcome, Aman! (b) greet (c) Welcome, name! (d) Aman
  15. 15.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(3));
  16. 16.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 5));
  17. 17.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(22));
  18. 18.🧰 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(9) + fee(3));
  19. 19.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(39));
  20. 20.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(23));
  21. 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(12) + fee(5));
  22. 22.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir"));     (a) greet (b) Kabir (c) Well done, Kabir! (d) Well done, name!
  23. 23.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hi, name! (b) Hi, Kabir! (c) Kabir (d) greet
  24. 24.🧰 In function tip(bill), what is bill? (a) an event (b) a parameter (c) a loop (d) a screen
  25. 25.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hello, name! (b) greet (c) Hello, Zoya! (d) Zoya
  26. 26.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya"));     (a) Riya (b) Hi, name! (c) Hi, Riya! (d) greet
  27. 27.🧰 What is a function? (a) a type of phone (b) a list of colours (c) a named block of code (d) a screen size
  28. 28.🧰 How do you run (call) a function called greet? (a) #greet (b) run greet (c) greet[] (d) greet()
  29. 29.🧰 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(9));
  30. 30.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(36));
  31. 31.🧰 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(7) + fee(8));
  32. 32.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(10));
  33. 33.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(2));
  34. 34.🧰 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));
  35. 35.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(40, 2));
  36. 36.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 5));
  37. 37.🧰 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(11) + fee(5));
  38. 38.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 6));
  39. 39.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Zoya (c) Hi, Zoya! (d) Hi, name!
  40. 40.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(50, 3));

Answer key

  1. Welcome, Riya!
  2. sends back a value
  3. 300
  4. 22
  5. Well done, Riya!
  6. 150
  7. 40
  8. 12
  9. 76
  10. Well done, Aman!
  11. 90
  12. 30
  13. to reuse code
  14. Welcome, Aman!
  15. 6
  16. 325
  17. 44
  18. 50
  19. 117
  20. 69
  21. 60
  22. Well done, Kabir!
  23. Hi, Kabir!
  24. a parameter
  25. Hello, Zoya!
  26. Hi, Riya!
  27. a named block of code
  28. greet()
  29. 120
  30. 108
  31. 60
  32. 30
  33. 40
  34. 20
  35. 80
  36. 350
  37. 60
  38. 90
  39. Hi, Zoya!
  40. 150

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