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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 97 · 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.🧰 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(1) + fee(4));
  2. 2.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Riya"));     (a) Riya (b) Welcome, Riya! (c) greet (d) Welcome, name!
  3. 3.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(15));
  4. 4.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(0));
  5. 5.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(35));
  6. 6.🧰 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(1) + fee(5));
  7. 7.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 2));
  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 30;
    }
    show(fee(5) + fee(4));
  9. 9.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(2));
  10. 10.🧰 Why write a function? (a) to make code longer (b) to slow the app (c) to hide errors (d) to reuse code
  11. 11.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(34));
  12. 12.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 5));
  13. 13.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(25));
  14. 14.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Meera"));     (a) Well done, name! (b) greet (c) Well done, Meera! (d) Meera
  15. 15.🧰 What is a function? (a) a named block of code (b) a list of colours (c) a screen size (d) a type of phone
  16. 16.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Meera"));     (a) Meera (b) Hi, name! (c) greet (d) Hi, Meera!
  17. 17.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(85, 5));
  18. 18.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(1));
  19. 19.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(1));
  20. 20.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 5));
  21. 21.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) Hi, Arjun! (c) greet (d) Hi, name!
  22. 22.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) greet (b) Riya (c) Hello, Riya! (d) Hello, name!
  23. 23.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) Hello, name! (c) greet (d) Hello, Arjun!
  24. 24.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(2));
  25. 25.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(28));
  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 20;
    }
    show(fee(10) + fee(8));
  27. 27.🧰 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(3));
  28. 28.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(3));
  29. 29.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(23));
  30. 30.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman"));     (a) Aman (b) Hi, Aman! (c) Hi, name! (d) greet
  31. 31.🧰 What does return do in a function? (a) repeats the code (b) closes the screen (c) deletes the app (d) sends back a value
  32. 32.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 3));
  33. 33.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(10));
  34. 34.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(4));
  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(3) + fee(9));
  36. 36.🧰 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(3) + fee(2));
  37. 37.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(1));
  38. 38.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) greet (b) Welcome, Arjun! (c) Welcome, name! (d) Arjun
  39. 39.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(5));
  40. 40.🧰 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(8));

Answer key

  1. 0
  2. Welcome, Riya!
  3. 30
  4. 30
  5. 70
  6. 20
  7. 200
  8. 30
  9. 40
  10. to reuse code
  11. 102
  12. 125
  13. 75
  14. Well done, Meera!
  15. a named block of code
  16. Hi, Meera!
  17. 425
  18. 40
  19. 30
  20. 325
  21. Hi, Arjun!
  22. Hello, Riya!
  23. Hello, Arjun!
  24. 80
  25. 84
  26. 40
  27. 20
  28. 50
  29. 69
  30. Hi, Aman!
  31. sends back a value
  32. 75
  33. 30
  34. 100
  35. 40
  36. 0
  37. 50
  38. Welcome, Arjun!
  39. 100
  40. 80

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