← Functions lesson New set →

App Dev Worksheet: Functions

App development lesson 20: Functions · Set 761 · 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 "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) Hello, Aman! (b) greet (c) Hello, name! (d) Aman
  2. 2.🧰 What is a function? (a) a type of phone (b) a list of colours (c) a named block of code (d) a screen size
  3. 3.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(2));
  4. 4.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(20));
  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 40;
    }
    show(fee(2) + fee(2));
  6. 6.🧰 How do you run (call) a function called greet? (a) greet[] (b) greet() (c) run greet (d) #greet
  7. 7.🧰 What does return do in a function? (a) deletes the app (b) repeats the code (c) closes the screen (d) sends back a value
  8. 8.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Zoya (c) Hi, name! (d) Hi, Zoya!
  9. 9.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(1));
  10. 10.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 3));
  11. 11.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Meera"));     (a) greet (b) Meera (c) Hello, Meera! (d) Hello, name!
  12. 12.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Meera"));     (a) greet (b) Well done, Meera! (c) Well done, name! (d) Meera
  13. 13.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(30));
  14. 14.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman"));     (a) Welcome, Aman! (b) Welcome, name! (c) Aman (d) greet
  15. 15.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(34));
  16. 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(5) + fee(7));
  17. 17.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(33));
  18. 18.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(45, 5));
  19. 19.🧰 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));
  20. 20.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(0));
  21. 21.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 2));
  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 60;
    }
    show(fee(5) + fee(8));
  23. 23.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 5));
  24. 24.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(1));
  25. 25.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(2));
  26. 26.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(7));
  27. 27.🧰 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(1) + fee(8));
  28. 28.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 5));
  29. 29.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) Welcome, Arjun! (b) Arjun (c) Welcome, name! (d) greet
  30. 30.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(34));
  31. 31.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(22));
  32. 32.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Well done, name! (b) greet (c) Riya (d) Well done, Riya!
  33. 33.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(1));
  34. 34.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hello, name! (b) Kabir (c) greet (d) Hello, Kabir!
  35. 35.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Zoya"));     (a) Zoya (b) Welcome, Zoya! (c) greet (d) Welcome, name!
  36. 36.🧰 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(2) + fee(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 60;
    }
    show(fee(2) + fee(5));
  38. 38.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(5));
  39. 39.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) Hi, Arjun! (c) greet (d) Hi, name!
  40. 40.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(11));

Answer key

  1. Hello, Aman!
  2. a named block of code
  3. 60
  4. 60
  5. 0
  6. greet()
  7. sends back a value
  8. Hi, Zoya!
  9. 60
  10. 210
  11. Hello, Meera!
  12. Well done, Meera!
  13. 60
  14. Welcome, Aman!
  15. 68
  16. 40
  17. 66
  18. 225
  19. 20
  20. 50
  21. 190
  22. 120
  23. 125
  24. 70
  25. 50
  26. 14
  27. 40
  28. 175
  29. Welcome, Arjun!
  30. 102
  31. 44
  32. Well done, Riya!
  33. 30
  34. Hello, Kabir!
  35. Welcome, Zoya!
  36. 30
  37. 60
  38. 80
  39. Hi, Arjun!
  40. 22

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