← Functions lesson New set →

App Dev Worksheet: Functions

App development lesson 20: Functions · Set 34 · 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 "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Well done, Riya! (b) Riya (c) Well done, name! (d) greet
  2. 2.🧰 Why write a function? (a) to hide errors (b) to slow the app (c) to reuse code (d) to make code longer
  3. 3.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 6));
  4. 4.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Riya"));     (a) Welcome, name! (b) greet (c) Welcome, Riya! (d) Riya
  5. 5.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(6));
  6. 6.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(3));
  7. 7.🧰 What does return do in a function? (a) sends back a value (b) repeats the code (c) closes the screen (d) deletes the app
  8. 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(10) + fee(10));
  9. 9.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Hello, name! (c) Aman (d) Hello, Aman!
  10. 10.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Meera"));     (a) greet (b) Welcome, Meera! (c) Welcome, name! (d) Meera
  11. 11.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(19));
  12. 12.🧰 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(4) + fee(5));
  13. 13.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) Well done, Arjun! (c) Well done, name! (d) greet
  14. 14.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(1));
  15. 15.🧰 What is a function? (a) a named block of code (b) a screen size (c) a list of colours (d) a type of phone
  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(7) + fee(9));
  17. 17.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 4));
  18. 18.🧰 How do you run (call) a function called greet? (a) run greet (b) greet[] (c) #greet (d) greet()
  19. 19.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(5));
  20. 20.🧰 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(3));
  21. 21.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) Hello, Riya! (b) Hello, name! (c) Riya (d) greet
  22. 22.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(3));
  23. 23.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Aman"));     (a) Aman (b) Well done, Aman! (c) greet (d) Well done, name!
  24. 24.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Zoya"));     (a) Zoya (b) Welcome, name! (c) Welcome, Zoya! (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 20;
    }
    show(fee(1) + fee(10));
  26. 26.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(8));
  27. 27.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(23));
  28. 28.🧰 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(8) + fee(12));
  29. 29.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(38));
  30. 30.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(2));
  31. 31.🧰 In function tip(bill), what is bill? (a) a loop (b) a parameter (c) a screen (d) an event
  32. 32.🧰 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(5) + fee(6));
  33. 33.🧰 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(4));
  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 50;
    }
    show(fee(3) + fee(12));
  35. 35.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) Welcome, name! (b) Arjun (c) greet (d) Welcome, Arjun!
  36. 36.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 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(4));
  38. 38.🧰 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(7));
  39. 39.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(19));
  40. 40.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(16));

Answer key

  1. Well done, Riya!
  2. to reuse code
  3. 210
  4. Welcome, Riya!
  5. 18
  6. 70
  7. sends back a value
  8. 40
  9. Hello, Aman!
  10. Welcome, Meera!
  11. 38
  12. 50
  13. Well done, Arjun!
  14. 60
  15. a named block of code
  16. 40
  17. 380
  18. greet()
  19. 110
  20. 0
  21. Hello, Riya!
  22. 6
  23. Well done, Aman!
  24. Welcome, Zoya!
  25. 20
  26. 16
  27. 69
  28. 80
  29. 76
  30. 70
  31. a parameter
  32. 60
  33. 30
  34. 50
  35. Welcome, Arjun!
  36. 75
  37. 0
  38. 60
  39. 57
  40. 32

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