← Functions lesson New set →

App Dev Worksheet: Functions

App development lesson 20: Functions · Set 838 · 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.🧰 Why write a function? (a) to reuse code (b) to hide errors (c) to slow the app (d) to make code longer
  2. 2.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir"));     (a) Well done, name! (b) Well done, Kabir! (c) greet (d) Kabir
  3. 3.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 6));
  4. 4.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(14));
  5. 5.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(0));
  6. 6.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(4));
  7. 7.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(0));
  8. 8.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(25));
  9. 9.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Welcome, Zoya! (c) Welcome, name! (d) Zoya
  10. 10.🧰 In function tip(bill), what is bill? (a) a loop (b) an event (c) a screen (d) a parameter
  11. 11.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(4));
  12. 12.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(1));
  13. 13.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Meera"));     (a) Meera (b) Hi, name! (c) Hi, Meera! (d) greet
  14. 14.🧰 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(3));
  15. 15.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(2));
  16. 16.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 3));
  17. 17.🧰 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(12) + fee(8));
  18. 18.🧰 What is a function? (a) a list of colours (b) a type of phone (c) a named block of code (d) a screen size
  19. 19.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 2));
  20. 20.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(2));
  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 40;
    }
    show(fee(5) + fee(10));
  22. 22.🧰 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(6) + fee(10));
  23. 23.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) greet (c) Hello, Arjun! (d) Hello, name!
  24. 24.🧰 How do you run (call) a function called greet? (a) run greet (b) greet[] (c) #greet (d) greet()
  25. 25.🧰 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(10) + fee(1));
  26. 26.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 4));
  27. 27.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(27));
  28. 28.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(1));
  29. 29.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) greet (b) Riya (c) Well done, name! (d) Well done, Riya!
  30. 30.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(5));
  31. 31.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(11));
  32. 32.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(4));
  33. 33.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) greet (b) Well done, name! (c) Well done, Arjun! (d) Arjun
  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 30;
    }
    show(fee(7) + fee(1));
  35. 35.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 4));
  36. 36.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(3));
  37. 37.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Arjun"));     (a) Hi, name! (b) Hi, Arjun! (c) Arjun (d) greet
  38. 38.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hello, Kabir! (b) greet (c) Hello, name! (d) Kabir
  39. 39.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(90, 6));
  40. 40.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(2));

Answer key

  1. to reuse code
  2. Well done, Kabir!
  3. 90
  4. 28
  5. 50
  6. 80
  7. 60
  8. 50
  9. Welcome, Zoya!
  10. a parameter
  11. 12
  12. 30
  13. Hi, Meera!
  14. 0
  15. 80
  16. 300
  17. 80
  18. a named block of code
  19. 200
  20. 40
  21. 80
  22. 60
  23. Hello, Arjun!
  24. greet()
  25. 40
  26. 260
  27. 54
  28. 50
  29. Well done, Riya!
  30. 100
  31. 22
  32. 100
  33. Well done, Arjun!
  34. 30
  35. 60
  36. 70
  37. Hi, Arjun!
  38. Hello, Kabir!
  39. 540
  40. 60

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