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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 684 · 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.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman"));     (a) Aman (b) Welcome, Aman! (c) Welcome, name! (d) greet
  2. 2.🧰 Why write a function? (a) to slow the app (b) to reuse code (c) to make code longer (d) to hide errors
  3. 3.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(13));
  4. 4.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Meera"));     (a) Hello, Meera! (b) Meera (c) greet (d) Hello, name!
  5. 5.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 4));
  6. 6.🧰 What does return do in a function? (a) sends back a value (b) repeats the code (c) closes the screen (d) deletes the app
  7. 7.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun"));     (a) Hello, name! (b) Arjun (c) greet (d) Hello, Arjun!
  8. 8.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya"));     (a) greet (b) Riya (c) Hi, name! (d) Hi, Riya!
  9. 9.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(0));
  10. 10.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(34));
  11. 11.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) Hello, Riya! (b) Hello, name! (c) greet (d) Riya
  12. 12.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) Kabir (b) Hello, name! (c) greet (d) Hello, Kabir!
  13. 13.🧰 How do you run (call) a function called greet? (a) #greet (b) greet[] (c) run greet (d) greet()
  14. 14.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(7));
  15. 15.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(21));
  16. 16.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Well done, Riya! (b) greet (c) Riya (d) Well done, name!
  17. 17.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(1));
  18. 18.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(11));
  19. 19.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(6));
  20. 20.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(4));
  21. 21.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Meera"));     (a) Meera (b) greet (c) Well done, Meera! (d) Well done, name!
  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(9) + fee(4));
  23. 23.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(3));
  24. 24.🧰 What is a function? (a) a list of colours (b) a screen size (c) a type of phone (d) a named block of code
  25. 25.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(1));
  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 30;
    }
    show(fee(10) + fee(5));
  27. 27.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir"));     (a) Well done, Kabir! (b) Well done, name! (c) greet (d) Kabir
  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 50;
    }
    show(fee(1) + fee(12));
  29. 29.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(8));
  30. 30.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Zoya (c) Well done, Zoya! (d) Well done, name!
  31. 31.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Kabir"));     (a) Kabir (b) greet (c) Hi, Kabir! (d) Hi, name!
  32. 32.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 3));
  33. 33.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(2));
  34. 34.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Zoya"));     (a) Welcome, Zoya! (b) Zoya (c) Welcome, name! (d) greet
  35. 35.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(40));
  36. 36.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(2));
  37. 37.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(36));
  38. 38.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(3));
  39. 39.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(90, 3));
  40. 40.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(1));

Answer key

  1. Welcome, Aman!
  2. to reuse code
  3. 26
  4. Hello, Meera!
  5. 40
  6. sends back a value
  7. Hello, Arjun!
  8. Hi, Riya!
  9. 30
  10. 102
  11. Hello, Riya!
  12. Hello, Kabir!
  13. greet()
  14. 14
  15. 42
  16. Well done, Riya!
  17. 60
  18. 33
  19. 12
  20. 80
  21. Well done, Meera!
  22. 20
  23. 80
  24. a named block of code
  25. 40
  26. 60
  27. Well done, Kabir!
  28. 50
  29. 16
  30. Well done, Zoya!
  31. Hi, Kabir!
  32. 60
  33. 50
  34. Welcome, Zoya!
  35. 80
  36. 80
  37. 108
  38. 60
  39. 270
  40. 50

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