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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 836 · 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.🧰 How do you run (call) a function called greet? (a) greet() (b) greet[] (c) #greet (d) run greet
  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 20;
    }
    show(fee(6) + fee(10));
  3. 3.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(5));
  4. 4.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(3));
  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 30;
    }
    show(fee(3) + fee(7));
  6. 6.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(12));
  7. 7.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(2));
  8. 8.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(22));
  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 50;
    }
    show(fee(3) + fee(1));
  10. 10.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun"));     (a) Hello, name! (b) Arjun (c) greet (d) Hello, Arjun!
  11. 11.🧰 What is a function? (a) a list of colours (b) a type of phone (c) a named block of code (d) a screen size
  12. 12.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(40, 4));
  13. 13.🧰 What does return do in a function? (a) repeats the code (b) closes the screen (c) deletes the app (d) sends back a value
  14. 14.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(50, 6));
  15. 15.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Riya (b) Well done, name! (c) greet (d) Well done, Riya!
  16. 16.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 2));
  17. 17.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Aman (c) Hello, name! (d) Hello, Aman!
  18. 18.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(0));
  19. 19.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(0));
  20. 20.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(8));
  21. 21.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) greet (b) Well done, name! (c) Well done, Arjun! (d) Arjun
  22. 22.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya"));     (a) Hi, name! (b) Riya (c) greet (d) Hi, Riya!
  23. 23.🧰 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(5) + fee(2));
  24. 24.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) greet (b) Riya (c) Hello, name! (d) Hello, Riya!
  25. 25.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman"));     (a) Hi, Aman! (b) Aman (c) Hi, name! (d) greet
  26. 26.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(11));
  27. 27.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Arjun"));     (a) Hi, Arjun! (b) Arjun (c) Hi, name! (d) greet
  28. 28.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 5));
  29. 29.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(0));
  30. 30.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(14));
  31. 31.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(4));
  32. 32.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(31));
  33. 33.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(1));
  34. 34.🧰 Why write a function? (a) to hide errors (b) to make code longer (c) to slow the app (d) to reuse code
  35. 35.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir"));     (a) Well done, name! (b) Kabir (c) greet (d) Well done, Kabir!
  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 50;
    }
    show(fee(11) + fee(10));
  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 40;
    }
    show(fee(11) + fee(7));
  38. 38.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(35));
  39. 39.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(1));
  40. 40.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 3));

Answer key

  1. greet()
  2. 40
  3. 110
  4. 80
  5. 30
  6. 36
  7. 70
  8. 44
  9. 0
  10. Hello, Arjun!
  11. a named block of code
  12. 160
  13. sends back a value
  14. 300
  15. Well done, Riya!
  16. 140
  17. Hello, Aman!
  18. 20
  19. 30
  20. 16
  21. Well done, Arjun!
  22. Hi, Riya!
  23. 50
  24. Hello, Riya!
  25. Hi, Aman!
  26. 22
  27. Hi, Arjun!
  28. 500
  29. 60
  30. 28
  31. 90
  32. 93
  33. 70
  34. to reuse code
  35. Well done, Kabir!
  36. 100
  37. 80
  38. 105
  39. 50
  40. 30

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