← Functions lesson New set →

App Dev Worksheet: Functions

App development lesson 20: Functions · Set 146 · 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.🧰 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(8) + fee(5));
  2. 2.🧰 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(2));
  3. 3.🧰 In function tip(bill), what is bill? (a) a screen (b) a loop (c) a parameter (d) an event
  4. 4.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 4));
  5. 5.🧰 How do you run (call) a function called greet? (a) run greet (b) greet[] (c) #greet (d) greet()
  6. 6.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(5));
  7. 7.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) greet (b) Arjun (c) Well done, Arjun! (d) Well done, name!
  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 30;
    }
    show(fee(3) + fee(8));
  9. 9.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(7));
  10. 10.🧰 What is a function? (a) a type of phone (b) a list of colours (c) a named block of code (d) a screen size
  11. 11.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(29));
  12. 12.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(20));
  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 "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) Hello, name! (b) greet (c) Aman (d) Hello, Aman!
  15. 15.🧰 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(9) + fee(10));
  16. 16.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Welcome, name! (c) Welcome, Aman! (d) Aman
  17. 17.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Well done, name! (b) Well done, Riya! (c) Riya (d) greet
  18. 18.🧰 Why write a function? (a) to slow the app (b) to hide errors (c) to make code longer (d) to reuse code
  19. 19.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(16));
  20. 20.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(34));
  21. 21.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) Hello, name! (b) Hello, Riya! (c) Riya (d) greet
  22. 22.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Meera"));     (a) greet (b) Meera (c) Welcome, Meera! (d) Welcome, name!
  23. 23.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(25));
  24. 24.🧰 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(7) + fee(3));
  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(12) + fee(9));
  26. 26.🧰 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(1) + fee(9));
  27. 27.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(11));
  28. 28.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir"));     (a) Welcome, Kabir! (b) Kabir (c) Welcome, name! (d) greet
  29. 29.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 5));
  30. 30.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) Kabir (b) Hello, Kabir! (c) greet (d) Hello, name!
  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 60;
    }
    show(fee(2) + fee(1));
  32. 32.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Meera"));     (a) Hi, name! (b) Meera (c) Hi, Meera! (d) greet
  33. 33.🧰 What does return do in a function? (a) sends back a value (b) repeats the code (c) closes the screen (d) deletes the app
  34. 34.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(2));
  35. 35.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(34));
  36. 36.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hi, Zoya! (b) greet (c) Hi, name! (d) Zoya
  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(11) + fee(6));
  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 60;
    }
    show(fee(6) + fee(7));
  39. 39.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun"));     (a) Hello, name! (b) Hello, Arjun! (c) greet (d) Arjun
  40. 40.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(32));

Answer key

  1. 120
  2. 30
  3. a parameter
  4. 400
  5. greet()
  6. 80
  7. Well done, Arjun!
  8. 30
  9. 14
  10. a named block of code
  11. 58
  12. 60
  13. 60
  14. Hello, Aman!
  15. 60
  16. Welcome, Aman!
  17. Well done, Riya!
  18. to reuse code
  19. 32
  20. 68
  21. Hello, Riya!
  22. Welcome, Meera!
  23. 50
  24. 50
  25. 40
  26. 60
  27. 33
  28. Welcome, Kabir!
  29. 275
  30. Hello, Kabir!
  31. 0
  32. Hi, Meera!
  33. sends back a value
  34. 40
  35. 102
  36. Hi, Zoya!
  37. 120
  38. 120
  39. Hello, Arjun!
  40. 64

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