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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 835 · 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.🧰 In function tip(bill), what is bill? (a) a screen (b) a parameter (c) a loop (d) an event
  2. 2.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(18));
  3. 3.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) Hello, name! (b) Hello, Riya! (c) Riya (d) greet
  4. 4.🧰 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(11) + fee(11));
  5. 5.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 3));
  6. 6.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 3));
  7. 7.🧰 What is a function? (a) a screen size (b) a list of colours (c) a type of phone (d) a named block of code
  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(3) + fee(2));
  9. 9.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(8));
  10. 10.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman"));     (a) Hi, name! (b) Hi, Aman! (c) Aman (d) greet
  11. 11.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 6));
  12. 12.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(22));
  13. 13.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 3));
  14. 14.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(8));
  15. 15.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(1));
  16. 16.🧰 Why write a function? (a) to reuse code (b) to make code longer (c) to slow the app (d) to hide errors
  17. 17.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 4));
  18. 18.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir"));     (a) Well done, name! (b) Well done, Kabir! (c) greet (d) Kabir
  19. 19.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(16));
  20. 20.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(5));
  21. 21.🧰 How do you run (call) a function called greet? (a) #greet (b) greet[] (c) run greet (d) greet()
  22. 22.🧰 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(7));
  23. 23.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 4));
  24. 24.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) Welcome, Arjun! (b) Arjun (c) greet (d) Welcome, name!
  25. 25.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 4));
  26. 26.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(4));
  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 50;
    }
    show(fee(6) + fee(2));
  28. 28.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 3));
  29. 29.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hello, name! (b) greet (c) Hello, Zoya! (d) Zoya
  30. 30.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(0));
  31. 31.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya"));     (a) greet (b) Hi, name! (c) Hi, Riya! (d) Riya
  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 30;
    }
    show(fee(4) + fee(8));
  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 30;
    }
    show(fee(5) + fee(2));
  34. 34.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(11));
  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 60;
    }
    show(fee(10) + fee(1));
  36. 36.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(85, 3));
  37. 37.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Meera"));     (a) Meera (b) Hi, name! (c) Hi, Meera! (d) greet
  38. 38.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun"));     (a) greet (b) Arjun (c) Hello, Arjun! (d) Hello, name!
  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 50;
    }
    show(fee(3) + fee(2));
  40. 40.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 5));

Answer key

  1. a parameter
  2. 36
  3. Hello, Riya!
  4. 100
  5. 180
  6. 210
  7. a named block of code
  8. 0
  9. 16
  10. Hi, Aman!
  11. 390
  12. 44
  13. 195
  14. 24
  15. 40
  16. to reuse code
  17. 320
  18. Well done, Kabir!
  19. 32
  20. 80
  21. greet()
  22. 60
  23. 400
  24. Welcome, Arjun!
  25. 60
  26. 12
  27. 50
  28. 60
  29. Hello, Zoya!
  30. 50
  31. Hi, Riya!
  32. 30
  33. 30
  34. 22
  35. 60
  36. 255
  37. Hi, Meera!
  38. Hello, Arjun!
  39. 0
  40. 300

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