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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 674 · 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 "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) Zoya (b) Hi, name! (c) greet (d) Hi, Zoya!
  2. 2.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(25));
  3. 3.🧰 What does return do in a function? (a) repeats the code (b) deletes the app (c) sends back a value (d) closes the screen
  4. 4.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(14));
  5. 5.🧰 Why write a function? (a) to slow the app (b) to make code longer (c) to reuse code (d) to hide errors
  6. 6.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 3));
  7. 7.🧰 In function tip(bill), what is bill? (a) a screen (b) a loop (c) a parameter (d) an event
  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 60;
    }
    show(fee(7) + fee(2));
  9. 9.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(2));
  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 20;
    }
    show(fee(2) + fee(8));
  11. 11.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(33));
  12. 12.🧰 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(5));
  13. 13.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(40, 4));
  14. 14.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir"));     (a) Welcome, Kabir! (b) Kabir (c) greet (d) Welcome, name!
  15. 15.🧰 What is a function? (a) a named block of code (b) a type of phone (c) a screen size (d) a list of colours
  16. 16.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) greet (b) Hello, name! (c) Riya (d) Hello, Riya!
  17. 17.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hi, name! (b) greet (c) Kabir (d) Hi, Kabir!
  18. 18.🧰 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(6) + fee(2));
  19. 19.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(4));
  20. 20.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 3));
  21. 21.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 3));
  22. 22.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 3));
  23. 23.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(37));
  24. 24.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 5));
  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 20;
    }
    show(fee(5) + fee(3));
  26. 26.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(4));
  27. 27.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya"));     (a) Hi, name! (b) Riya (c) Hi, Riya! (d) greet
  28. 28.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(4));
  29. 29.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Meera"));     (a) Meera (b) Hello, Meera! (c) Hello, name! (d) greet
  30. 30.🧰 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(7) + fee(9));
  31. 31.🧰 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(4) + fee(12));
  32. 32.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(3));
  33. 33.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(4));
  34. 34.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(39));
  35. 35.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 3));
  36. 36.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun"));     (a) greet (b) Hello, Arjun! (c) Hello, name! (d) Arjun
  37. 37.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 6));
  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 30;
    }
    show(fee(9) + fee(11));
  39. 39.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(1));
  40. 40.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(3));

Answer key

  1. Hi, Zoya!
  2. 75
  3. sends back a value
  4. 28
  5. to reuse code
  6. 90
  7. a parameter
  8. 60
  9. 80
  10. 20
  11. 99
  12. 80
  13. 160
  14. Welcome, Kabir!
  15. a named block of code
  16. Hello, Riya!
  17. Hi, Kabir!
  18. 40
  19. 80
  20. 75
  21. 180
  22. 195
  23. 111
  24. 75
  25. 20
  26. 60
  27. Hi, Riya!
  28. 12
  29. Hello, Meera!
  30. 120
  31. 50
  32. 90
  33. 8
  34. 117
  35. 60
  36. Hello, Arjun!
  37. 150
  38. 60
  39. 70
  40. 80

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