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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 422 · 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 "Well done, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Well done, Aman! (c) Aman (d) Well done, name!
  2. 2.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(4));
  3. 3.🧰 What is a function? (a) a type of phone (b) a list of colours (c) a named block of code (d) a screen size
  4. 4.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(5));
  5. 5.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) Welcome, Arjun! (c) greet (d) Welcome, name!
  6. 6.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Riya (b) Well done, name! (c) greet (d) Well done, Riya!
  7. 7.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(0));
  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 40;
    }
    show(fee(3) + fee(5));
  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 60;
    }
    show(fee(2) + fee(2));
  10. 10.🧰 How do you run (call) a function called greet? (a) run greet (b) greet() (c) greet[] (d) #greet
  11. 11.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(5));
  12. 12.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 5));
  13. 13.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(5));
  14. 14.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(40));
  15. 15.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 3));
  16. 16.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 6));
  17. 17.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(3));
  18. 18.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(3));
  19. 19.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(1));
  20. 20.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Hello, Aman! (c) Hello, name! (d) Aman
  21. 21.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 2));
  22. 22.🧰 In function tip(bill), what is bill? (a) a parameter (b) a screen (c) an event (d) a loop
  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 60;
    }
    show(fee(11) + fee(10));
  24. 24.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) greet (b) Riya (c) Hello, Riya! (d) Hello, name!
  25. 25.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hello, Kabir! (b) greet (c) Hello, name! (d) Kabir
  26. 26.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(8));
  27. 27.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(16));
  28. 28.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(3));
  29. 29.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir"));     (a) Welcome, name! (b) Kabir (c) greet (d) Welcome, Kabir!
  30. 30.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(25));
  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(8) + fee(9));
  32. 32.🧰 What does return do in a function? (a) repeats the code (b) closes the screen (c) sends back a value (d) deletes the app
  33. 33.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(3));
  34. 34.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(2));
  35. 35.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hello, name! (b) Hello, Zoya! (c) greet (d) Zoya
  36. 36.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(0));
  37. 37.🧰 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(10) + fee(8));
  38. 38.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(0));
  39. 39.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Zoya"));     (a) Zoya (b) greet (c) Welcome, name! (d) Welcome, Zoya!
  40. 40.🧰 Why write a function? (a) to hide errors (b) to make code longer (c) to slow the app (d) to reuse code

Answer key

  1. Well done, Aman!
  2. 60
  3. a named block of code
  4. 80
  5. Welcome, Arjun!
  6. Well done, Riya!
  7. 30
  8. 40
  9. 0
  10. greet()
  11. 90
  12. 300
  13. 70
  14. 80
  15. 60
  16. 120
  17. 80
  18. 50
  19. 40
  20. Hello, Aman!
  21. 110
  22. a parameter
  23. 120
  24. Hello, Riya!
  25. Hello, Kabir!
  26. 24
  27. 32
  28. 60
  29. Welcome, Kabir!
  30. 50
  31. 60
  32. sends back a value
  33. 6
  34. 40
  35. Hello, Zoya!
  36. 20
  37. 80
  38. 50
  39. Welcome, Zoya!
  40. to reuse code

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