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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 439 · 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 40;
    }
    show(fee(1) + fee(10));
  2. 2.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 5));
  3. 3.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(15));
  4. 4.🧰 Why write a function? (a) to make code longer (b) to slow the app (c) to hide errors (d) to reuse code
  5. 5.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(30));
  6. 6.🧰 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(12));
  7. 7.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Meera"));     (a) Hello, name! (b) Hello, Meera! (c) greet (d) Meera
  8. 8.🧰 What is a function? (a) a named block of code (b) a list of colours (c) a type of phone (d) a screen size
  9. 9.🧰 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(3) + fee(12));
  10. 10.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(5));
  11. 11.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(38));
  12. 12.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) Well done, Arjun! (b) Well done, name! (c) Arjun (d) greet
  13. 13.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman"));     (a) Welcome, name! (b) greet (c) Welcome, Aman! (d) Aman
  14. 14.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 2));
  15. 15.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(34));
  16. 16.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 2));
  17. 17.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(3));
  18. 18.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(21));
  19. 19.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(5));
  20. 20.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 2));
  21. 21.🧰 How do you run (call) a function called greet? (a) run greet (b) greet[] (c) #greet (d) greet()
  22. 22.🧰 In function tip(bill), what is bill? (a) a parameter (b) a loop (c) a screen (d) an event
  23. 23.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(18));
  24. 24.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(4));
  25. 25.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 3));
  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(12));
  27. 27.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir"));     (a) Kabir (b) Well done, Kabir! (c) Well done, name! (d) greet
  28. 28.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(3));
  29. 29.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(12));
  30. 30.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(17));
  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(11) + fee(2));
  32. 32.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Zoya (c) Hi, Zoya! (d) Hi, name!
  33. 33.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(9));
  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(6) + fee(3));
  35. 35.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Meera"));     (a) Well done, Meera! (b) greet (c) Well done, name! (d) Meera
  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(4) + fee(4));
  37. 37.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(7));
  38. 38.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman"));     (a) Aman (b) Hi, Aman! (c) Hi, name! (d) greet
  39. 39.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(1));
  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 20;
    }
    show(fee(5) + fee(2));

Answer key

  1. 40
  2. 50
  3. 30
  4. to reuse code
  5. 90
  6. 60
  7. Hello, Meera!
  8. a named block of code
  9. 40
  10. 90
  11. 114
  12. Well done, Arjun!
  13. Welcome, Aman!
  14. 30
  15. 102
  16. 60
  17. 90
  18. 42
  19. 100
  20. 20
  21. greet()
  22. a parameter
  23. 54
  24. 80
  25. 285
  26. 60
  27. Well done, Kabir!
  28. 80
  29. 36
  30. 34
  31. 60
  32. Hi, Zoya!
  33. 27
  34. 50
  35. Well done, Meera!
  36. 0
  37. 14
  38. Hi, Aman!
  39. 30
  40. 20

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