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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 991 · 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 number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(0));
  2. 2.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Hi, Aman! (c) Aman (d) Hi, name!
  3. 3.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) greet (b) Hello, Kabir! (c) Hello, name! (d) Kabir
  4. 4.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(26));
  5. 5.🧰 What does return do in a function? (a) closes the screen (b) deletes the app (c) sends back a value (d) repeats the code
  6. 6.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(12));
  7. 7.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 6));
  8. 8.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(37));
  9. 9.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 5));
  10. 10.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(36));
  11. 11.🧰 Why write a function? (a) to hide errors (b) to make code longer (c) to slow the app (d) to reuse code
  12. 12.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Well done, name! (b) Riya (c) greet (d) Well done, Riya!
  13. 13.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(24));
  14. 14.🧰 What is a function? (a) a screen size (b) a type of phone (c) a named block of code (d) a list of colours
  15. 15.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(4));
  16. 16.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Meera"));     (a) greet (b) Meera (c) Hello, name! (d) Hello, Meera!
  17. 17.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) greet (c) Hello, Arjun! (d) Hello, name!
  18. 18.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Meera"));     (a) Meera (b) Well done, name! (c) Well done, Meera! (d) greet
  19. 19.🧰 How do you run (call) a function called greet? (a) greet[] (b) run greet (c) #greet (d) greet()
  20. 20.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(33));
  21. 21.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) greet (b) Welcome, name! (c) Welcome, Arjun! (d) Arjun
  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 60;
    }
    show(fee(6) + fee(9));
  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(8) + fee(7));
  24. 24.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(4));
  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 30;
    }
    show(fee(8) + fee(10));
  26. 26.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Meera"));     (a) Welcome, Meera! (b) Welcome, name! (c) greet (d) Meera
  27. 27.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(7));
  28. 28.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Meera"));     (a) Hi, name! (b) Meera (c) Hi, Meera! (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 20;
    }
    show(fee(8) + fee(1));
  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 50;
    }
    show(fee(10) + fee(6));
  31. 31.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(40));
  32. 32.🧰 In function tip(bill), what is bill? (a) a loop (b) an event (c) a parameter (d) a screen
  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(6) + fee(3));
  34. 34.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Zoya"));     (a) Welcome, Zoya! (b) Welcome, name! (c) greet (d) Zoya
  35. 35.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(3));
  36. 36.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Hi, Zoya! (c) Hi, name! (d) Zoya
  37. 37.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(26));
  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 50;
    }
    show(fee(7) + fee(12));
  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 30;
    }
    show(fee(7) + fee(2));
  40. 40.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(5));

Answer key

  1. 30
  2. Hi, Aman!
  3. Hello, Kabir!
  4. 52
  5. sends back a value
  6. 36
  7. 150
  8. 111
  9. 350
  10. 72
  11. to reuse code
  12. Well done, Riya!
  13. 72
  14. a named block of code
  15. 80
  16. Hello, Meera!
  17. Hello, Arjun!
  18. Well done, Meera!
  19. greet()
  20. 99
  21. Welcome, Arjun!
  22. 120
  23. 60
  24. 90
  25. 60
  26. Welcome, Meera!
  27. 14
  28. Hi, Meera!
  29. 20
  30. 100
  31. 80
  32. a parameter
  33. 30
  34. Welcome, Zoya!
  35. 9
  36. Hi, Zoya!
  37. 78
  38. 100
  39. 30
  40. 90

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