← Functions lesson New set →

App Dev Worksheet: Functions

App development lesson 20: Functions · Set 632 · 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(3) + fee(3));
  2. 2.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(2));
  3. 3.🧰 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(6) + fee(12));
  4. 4.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Hello, name! (c) Zoya (d) Hello, Zoya!
  5. 5.🧰 Why write a function? (a) to reuse code (b) to hide errors (c) to make code longer (d) to slow the app
  6. 6.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) Kabir (b) greet (c) Hello, Kabir! (d) Hello, name!
  7. 7.🧰 In function tip(bill), what is bill? (a) a parameter (b) a loop (c) a screen (d) an event
  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(12) + fee(7));
  9. 9.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 6));
  10. 10.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(11));
  11. 11.🧰 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(2));
  12. 12.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(5));
  13. 13.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 3));
  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 50;
    }
    show(fee(11) + fee(1));
  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 50;
    }
    show(fee(7) + fee(5));
  16. 16.🧰 How do you run (call) a function called greet? (a) #greet (b) greet[] (c) greet() (d) run greet
  17. 17.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(2));
  18. 18.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(3));
  19. 19.🧰 What is a function? (a) a type of phone (b) a list of colours (c) a screen size (d) a named block of code
  20. 20.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(11));
  21. 21.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(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 20;
    }
    show(fee(11) + fee(1));
  23. 23.🧰 What does return do in a function? (a) repeats the code (b) closes the screen (c) sends back a value (d) deletes the app
  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(10) + fee(4));
  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(4) + fee(11));
  26. 26.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(26));
  27. 27.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(5));
  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 30;
    }
    show(fee(3) + fee(7));
  29. 29.🧰 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
  30. 30.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(5));
  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(5) + fee(6));
  32. 32.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hi, name! (b) greet (c) Zoya (d) Hi, Zoya!
  33. 33.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) Aman (b) greet (c) Hello, name! (d) Hello, Aman!
  34. 34.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(18));
  35. 35.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir"));     (a) Welcome, name! (b) Welcome, Kabir! (c) greet (d) Kabir
  36. 36.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(9));
  37. 37.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 2));
  38. 38.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(0));
  39. 39.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 5));
  40. 40.🧰 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(7));

Answer key

  1. 0
  2. 40
  3. 40
  4. Hello, Zoya!
  5. to reuse code
  6. Hello, Kabir!
  7. a parameter
  8. 40
  9. 210
  10. 33
  11. 0
  12. 10
  13. 165
  14. 50
  15. 100
  16. greet()
  17. 50
  18. 9
  19. a named block of code
  20. 22
  21. 70
  22. 20
  23. sends back a value
  24. 50
  25. 40
  26. 78
  27. 100
  28. 30
  29. Well done, Meera!
  30. 15
  31. 120
  32. Hi, Zoya!
  33. Hello, Aman!
  34. 54
  35. Welcome, Kabir!
  36. 18
  37. 40
  38. 20
  39. 75
  40. 80

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