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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 955 · 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 return do in a function? (a) closes the screen (b) deletes the app (c) repeats the code (d) sends back a value
  2. 2.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(1));
  3. 3.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 6));
  4. 4.🧰 Why write a function? (a) to slow the app (b) to reuse code (c) to hide errors (d) to make code longer
  5. 5.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(2));
  6. 6.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(5));
  7. 7.🧰 How do you run (call) a function called greet? (a) #greet (b) greet() (c) run greet (d) greet[]
  8. 8.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(14));
  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(10) + fee(10));
  10. 10.🧰 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(7) + fee(2));
  11. 11.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 6));
  12. 12.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 4));
  13. 13.🧰 What is a function? (a) a list of colours (b) a named block of code (c) a type of phone (d) a screen size
  14. 14.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 3));
  15. 15.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(5));
  16. 16.🧰 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(11));
  17. 17.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hello, Kabir! (b) Hello, name! (c) Kabir (d) greet
  18. 18.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Meera"));     (a) Meera (b) greet (c) Welcome, name! (d) Welcome, Meera!
  19. 19.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman"));     (a) Aman (b) Welcome, Aman! (c) Welcome, name! (d) greet
  20. 20.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Riya (b) greet (c) Well done, Riya! (d) Well done, name!
  21. 21.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(2));
  22. 22.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(1));
  23. 23.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) Zoya (b) Hello, name! (c) Hello, Zoya! (d) greet
  24. 24.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(19));
  25. 25.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 6));
  26. 26.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(0));
  27. 27.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 2));
  28. 28.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 2));
  29. 29.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 4));
  30. 30.🧰 In function tip(bill), what is bill? (a) a parameter (b) an event (c) a loop (d) a screen
  31. 31.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(39));
  32. 32.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Aman (c) Well done, Aman! (d) Well done, name!
  33. 33.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(0));
  34. 34.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) greet (c) Hi, name! (d) Hi, Arjun!
  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.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(0));
  37. 37.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(1));
  38. 38.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(35));
  39. 39.🧰 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(12) + fee(9));
  40. 40.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 4));

Answer key

  1. sends back a value
  2. 60
  3. 150
  4. to reuse code
  5. 70
  6. 110
  7. greet()
  8. 42
  9. 80
  10. 40
  11. 180
  12. 400
  13. a named block of code
  14. 195
  15. 70
  16. 40
  17. Hello, Kabir!
  18. Welcome, Meera!
  19. Welcome, Aman!
  20. Well done, Riya!
  21. 50
  22. 30
  23. Hello, Zoya!
  24. 57
  25. 120
  26. 30
  27. 40
  28. 50
  29. 80
  30. a parameter
  31. 78
  32. Well done, Aman!
  33. 20
  34. Hi, Arjun!
  35. Well done, Meera!
  36. 50
  37. 50
  38. 70
  39. 100
  40. 60

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