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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 563 · 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.🧰 Why write a function? (a) to make code longer (b) to slow the app (c) to hide errors (d) to reuse code
  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 50;
    }
    show(fee(6) + fee(6));
  3. 3.🧰 What is a function? (a) a list of colours (b) a type of phone (c) a screen size (d) a named block of code
  4. 4.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) greet (b) Riya (c) Hello, name! (d) Hello, Riya!
  5. 5.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(90, 6));
  6. 6.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(7));
  7. 7.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(29));
  8. 8.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(19));
  9. 9.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 2));
  10. 10.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Zoya"));     (a) Zoya (b) greet (c) Well done, name! (d) Well done, Zoya!
  11. 11.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(28));
  12. 12.🧰 What does return do in a function? (a) deletes the app (b) repeats the code (c) sends back a value (d) closes the screen
  13. 13.🧰 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(11) + fee(8));
  14. 14.🧰 In function tip(bill), what is bill? (a) a parameter (b) an event (c) a screen (d) a loop
  15. 15.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(33));
  16. 16.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir"));     (a) Welcome, name! (b) Kabir (c) greet (d) Welcome, Kabir!
  17. 17.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya"));     (a) Hi, Riya! (b) Hi, name! (c) Riya (d) greet
  18. 18.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) Well done, name! (b) Well done, Arjun! (c) Arjun (d) greet
  19. 19.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(5));
  20. 20.🧰 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(4) + fee(8));
  21. 21.🧰 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(12) + fee(11));
  22. 22.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(1));
  23. 23.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(5));
  24. 24.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 4));
  25. 25.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Well done, Riya! (b) Well done, name! (c) greet (d) Riya
  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 40;
    }
    show(fee(2) + fee(1));
  27. 27.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) Hello, Aman! (b) greet (c) Aman (d) Hello, name!
  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 30;
    }
    show(fee(12) + fee(7));
  29. 29.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(6));
  30. 30.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Meera"));     (a) Well done, Meera! (b) Meera (c) Well done, name! (d) greet
  31. 31.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(40, 3));
  32. 32.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(1));
  33. 33.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(9));
  34. 34.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) greet (b) Hello, Kabir! (c) Kabir (d) Hello, name!
  35. 35.🧰 How do you run (call) a function called greet? (a) #greet (b) greet() (c) greet[] (d) run greet
  36. 36.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(21));
  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 20;
    }
    show(fee(12) + fee(6));
  38. 38.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(3));
  39. 39.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(17));
  40. 40.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(5));

Answer key

  1. to reuse code
  2. 100
  3. a named block of code
  4. Hello, Riya!
  5. 540
  6. 14
  7. 87
  8. 38
  9. 110
  10. Well done, Zoya!
  11. 84
  12. sends back a value
  13. 60
  14. a parameter
  15. 66
  16. Welcome, Kabir!
  17. Hi, Riya!
  18. Well done, Arjun!
  19. 100
  20. 60
  21. 60
  22. 60
  23. 90
  24. 320
  25. Well done, Riya!
  26. 0
  27. Hello, Aman!
  28. 60
  29. 12
  30. Well done, Meera!
  31. 120
  32. 70
  33. 27
  34. Hello, Kabir!
  35. greet()
  36. 42
  37. 40
  38. 90
  39. 34
  40. 70

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