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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 806 · 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 60;
    }
    show(fee(1) + fee(2));
  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 40;
    }
    show(fee(6) + fee(3));
  3. 3.🧰 How do you run (call) a function called greet? (a) greet() (b) run greet (c) greet[] (d) #greet
  4. 4.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Welcome, name! (c) Welcome, Aman! (d) Aman
  5. 5.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(1));
  6. 6.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 3));
  7. 7.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(1));
  8. 8.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(0));
  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 50;
    }
    show(fee(5) + fee(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 30;
    }
    show(fee(1) + fee(1));
  11. 11.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(40, 5));
  12. 12.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(0));
  13. 13.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) greet (c) Hello, Arjun! (d) Hello, name!
  14. 14.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(19));
  15. 15.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 3));
  16. 16.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Hi, Aman! (c) Aman (d) Hi, name!
  17. 17.🧰 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(6));
  18. 18.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(36));
  19. 19.🧰 What does return do in a function? (a) repeats the code (b) closes the screen (c) deletes the app (d) sends back a value
  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 40;
    }
    show(fee(7) + fee(1));
  21. 21.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(1));
  22. 22.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Aman"));     (a) Well done, name! (b) Aman (c) Well done, Aman! (d) greet
  23. 23.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(24));
  24. 24.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(5));
  25. 25.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hi, name! (b) Zoya (c) greet (d) Hi, Zoya!
  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 50;
    }
    show(fee(7) + fee(12));
  27. 27.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(16));
  28. 28.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Arjun"));     (a) Hi, name! (b) Hi, Arjun! (c) Arjun (d) greet
  29. 29.🧰 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(7) + fee(2));
  30. 30.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hello, name! (b) Kabir (c) greet (d) Hello, Kabir!
  31. 31.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 6));
  32. 32.🧰 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(4));
  33. 33.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(2));
  34. 34.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(2));
  35. 35.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 6));
  36. 36.🧰 Why write a function? (a) to reuse code (b) to make code longer (c) to slow the app (d) to hide errors
  37. 37.🧰 What is a function? (a) a named block of code (b) a type of phone (c) a screen size (d) a list of colours
  38. 38.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(1));
  39. 39.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(7));
  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 30;
    }
    show(fee(12) + fee(2));

Answer key

  1. 0
  2. 40
  3. greet()
  4. Welcome, Aman!
  5. 40
  6. 285
  7. 70
  8. 40
  9. 50
  10. 0
  11. 200
  12. 50
  13. Hello, Arjun!
  14. 38
  15. 45
  16. Hi, Aman!
  17. 80
  18. 108
  19. sends back a value
  20. 40
  21. 50
  22. Well done, Aman!
  23. 48
  24. 70
  25. Hi, Zoya!
  26. 100
  27. 32
  28. Hi, Arjun!
  29. 30
  30. Hello, Kabir!
  31. 180
  32. 40
  33. 50
  34. 70
  35. 420
  36. to reuse code
  37. a named block of code
  38. 30
  39. 14
  40. 30

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