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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 648 · 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.🧰 In function tip(bill), what is bill? (a) a loop (b) a screen (c) a parameter (d) an event
  2. 2.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 3));
  3. 3.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) Hello, name! (b) greet (c) Aman (d) Hello, Aman!
  4. 4.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(2));
  5. 5.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun"));     (a) greet (b) Hello, name! (c) Hello, Arjun! (d) Arjun
  6. 6.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(3));
  7. 7.🧰 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(8) + fee(8));
  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 40;
    }
    show(fee(12) + fee(11));
  9. 9.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 3));
  10. 10.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(2));
  11. 11.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(3));
  12. 12.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(14));
  13. 13.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(5));
  14. 14.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Meera"));     (a) greet (b) Meera (c) Hi, Meera! (d) Hi, name!
  15. 15.🧰 What is a function? (a) a type of phone (b) a named block of code (c) a screen size (d) a list of colours
  16. 16.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(40));
  17. 17.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(11));
  18. 18.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(13));
  19. 19.🧰 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(8));
  20. 20.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 6));
  21. 21.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Meera"));     (a) greet (b) Welcome, name! (c) Meera (d) Welcome, Meera!
  22. 22.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(19));
  23. 23.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya"));     (a) greet (b) Hi, name! (c) Hi, Riya! (d) Riya
  24. 24.🧰 What does return do in a function? (a) sends back a value (b) closes the screen (c) deletes the app (d) repeats the code
  25. 25.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Riya"));     (a) greet (b) Riya (c) Welcome, name! (d) Welcome, Riya!
  26. 26.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(5));
  27. 27.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(7));
  28. 28.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(0));
  29. 29.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hello, name! (b) Kabir (c) greet (d) Hello, Kabir!
  30. 30.🧰 How do you run (call) a function called greet? (a) #greet (b) run greet (c) greet[] (d) greet()
  31. 31.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hi, name! (b) Zoya (c) greet (d) Hi, Zoya!
  32. 32.🧰 Why write a function? (a) to hide errors (b) to slow the app (c) to make code longer (d) to reuse code
  33. 33.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Zoya"));     (a) Well done, name! (b) greet (c) Zoya (d) Well done, Zoya!
  34. 34.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 6));
  35. 35.🧰 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(9) + fee(2));
  36. 36.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(4));
  37. 37.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 2));
  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 50;
    }
    show(fee(3) + fee(6));
  39. 39.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(14));
  40. 40.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 3));

Answer key

  1. a parameter
  2. 210
  3. Hello, Aman!
  4. 50
  5. Hello, Arjun!
  6. 80
  7. 60
  8. 80
  9. 300
  10. 60
  11. 9
  12. 42
  13. 100
  14. Hi, Meera!
  15. a named block of code
  16. 120
  17. 22
  18. 39
  19. 120
  20. 420
  21. Welcome, Meera!
  22. 38
  23. Hi, Riya!
  24. sends back a value
  25. Welcome, Riya!
  26. 15
  27. 14
  28. 40
  29. Hello, Kabir!
  30. greet()
  31. Hi, Zoya!
  32. to reuse code
  33. Well done, Zoya!
  34. 360
  35. 40
  36. 100
  37. 60
  38. 50
  39. 28
  40. 240

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