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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 258 · 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(1));
  2. 2.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(0));
  3. 3.🧰 In function tip(bill), what is bill? (a) a loop (b) a parameter (c) an event (d) a screen
  4. 4.🧰 What does return do in a function? (a) deletes the app (b) closes the screen (c) sends back a value (d) repeats the code
  5. 5.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(4));
  6. 6.🧰 How do you run (call) a function called greet? (a) greet[] (b) run greet (c) #greet (d) greet()
  7. 7.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Meera"));     (a) greet (b) Hi, Meera! (c) Meera (d) Hi, name!
  8. 8.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hi, name! (b) Zoya (c) Hi, Zoya! (d) greet
  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 60;
    }
    show(fee(2) + fee(10));
  10. 10.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) Well done, Arjun! (b) Well done, name! (c) greet (d) Arjun
  11. 11.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 2));
  12. 12.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) Aman (b) Hello, Aman! (c) greet (d) Hello, name!
  13. 13.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(27));
  14. 14.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(3));
  15. 15.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(4));
  16. 16.🧰 What is a function? (a) a type of phone (b) a screen size (c) a list of colours (d) a named block of code
  17. 17.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(10));
  18. 18.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(1));
  19. 19.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(10));
  20. 20.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Zoya"));     (a) Well done, Zoya! (b) Zoya (c) greet (d) Well done, name!
  21. 21.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 2));
  22. 22.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(13));
  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 40;
    }
    show(fee(3) + fee(7));
  24. 24.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Aman (c) Welcome, Aman! (d) Welcome, name!
  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 60;
    }
    show(fee(11) + fee(9));
  26. 26.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(1));
  27. 27.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(15));
  28. 28.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya"));     (a) Hi, Riya! (b) Hi, name! (c) greet (d) Riya
  29. 29.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 6));
  30. 30.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(29));
  31. 31.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) Welcome, name! (b) greet (c) Arjun (d) Welcome, Arjun!
  32. 32.🧰 Why write a function? (a) to slow the app (b) to make code longer (c) to hide errors (d) to reuse code
  33. 33.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 6));
  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 60;
    }
    show(fee(3) + fee(3));
  35. 35.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(35));
  36. 36.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(0));
  37. 37.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Aman"));     (a) Well done, Aman! (b) Well done, name! (c) greet (d) Aman
  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 20;
    }
    show(fee(8) + fee(5));
  39. 39.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(4));
  40. 40.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(50, 6));

Answer key

  1. 0
  2. 20
  3. a parameter
  4. sends back a value
  5. 90
  6. greet()
  7. Hi, Meera!
  8. Hi, Zoya!
  9. 60
  10. Well done, Arjun!
  11. 200
  12. Hello, Aman!
  13. 81
  14. 50
  15. 100
  16. a named block of code
  17. 30
  18. 30
  19. 20
  20. Well done, Zoya!
  21. 160
  22. 39
  23. 40
  24. Welcome, Aman!
  25. 120
  26. 50
  27. 30
  28. Hi, Riya!
  29. 570
  30. 87
  31. Welcome, Arjun!
  32. to reuse code
  33. 360
  34. 0
  35. 105
  36. 50
  37. Well done, Aman!
  38. 40
  39. 60
  40. 300

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