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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 242 · 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 "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) Riya (b) Hello, Riya! (c) Hello, name! (d) greet
  2. 2.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(4));
  3. 3.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(32));
  4. 4.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) Welcome, name! (b) Arjun (c) greet (d) Welcome, Arjun!
  5. 5.🧰 Why write a function? (a) to reuse code (b) to slow the app (c) to make code longer (d) to hide errors
  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(11) + fee(1));
  7. 7.🧰 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(10));
  8. 8.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Meera"));     (a) Well done, name! (b) Well done, Meera! (c) Meera (d) greet
  9. 9.🧰 In function tip(bill), what is bill? (a) a loop (b) a screen (c) an event (d) a parameter
  10. 10.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(1));
  11. 11.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hello, name! (b) greet (c) Kabir (d) Hello, Kabir!
  12. 12.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Zoya"));     (a) Zoya (b) Welcome, name! (c) greet (d) Welcome, Zoya!
  13. 13.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(38));
  14. 14.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Aman (c) Hello, Aman! (d) Hello, name!
  15. 15.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 6));
  16. 16.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hi, name! (b) greet (c) Kabir (d) Hi, Kabir!
  17. 17.🧰 What is a function? (a) a screen size (b) a named block of code (c) a type of phone (d) a list of colours
  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(8) + fee(8));
  19. 19.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 6));
  20. 20.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya"));     (a) Riya (b) Hi, Riya! (c) Hi, name! (d) greet
  21. 21.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 4));
  22. 22.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 2));
  23. 23.🧰 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(3) + fee(3));
  24. 24.🧰 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(12));
  25. 25.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(30));
  26. 26.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) Well done, Arjun! (b) greet (c) Well done, name! (d) Arjun
  27. 27.🧰 How do you run (call) a function called greet? (a) greet() (b) #greet (c) greet[] (d) run greet
  28. 28.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(25));
  29. 29.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 3));
  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 40;
    }
    show(fee(3) + fee(6));
  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 30;
    }
    show(fee(1) + fee(7));
  32. 32.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(4));
  33. 33.🧰 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(2));
  34. 34.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(2));
  35. 35.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(0));
  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 40;
    }
    show(fee(1) + fee(10));
  37. 37.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(14));
  38. 38.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(11));
  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 40;
    }
    show(fee(1) + fee(1));
  40. 40.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 4));

Answer key

  1. Hello, Riya!
  2. 90
  3. 96
  4. Welcome, Arjun!
  5. to reuse code
  6. 20
  7. 100
  8. Well done, Meera!
  9. a parameter
  10. 50
  11. Hello, Kabir!
  12. Welcome, Zoya!
  13. 114
  14. Hello, Aman!
  15. 180
  16. Hi, Kabir!
  17. a named block of code
  18. 80
  19. 480
  20. Hi, Riya!
  21. 140
  22. 140
  23. 0
  24. 40
  25. 90
  26. Well done, Arjun!
  27. greet()
  28. 50
  29. 90
  30. 40
  31. 30
  32. 70
  33. 50
  34. 60
  35. 20
  36. 40
  37. 28
  38. 33
  39. 0
  40. 400

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