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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 756 · 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 "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) Welcome, name! (b) Arjun (c) Welcome, Arjun! (d) greet
  2. 2.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(30));
  3. 3.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(9));
  4. 4.🧰 What is a function? (a) a named block of code (b) a type of phone (c) a list of colours (d) a screen size
  5. 5.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(1));
  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(9) + fee(8));
  7. 7.🧰 What does return do in a function? (a) closes the screen (b) repeats the code (c) deletes the app (d) sends back a value
  8. 8.🧰 In function tip(bill), what is bill? (a) a screen (b) an event (c) a parameter (d) a loop
  9. 9.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(40));
  10. 10.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hello, Kabir! (b) Kabir (c) greet (d) Hello, name!
  11. 11.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(2));
  12. 12.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) Hello, name! (b) Hello, Riya! (c) greet (d) Riya
  13. 13.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(16));
  14. 14.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Well done, name! (c) Well done, Zoya! (d) Zoya
  15. 15.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(0));
  16. 16.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 4));
  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(2) + fee(1));
  18. 18.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 2));
  19. 19.🧰 How do you run (call) a function called greet? (a) #greet (b) greet() (c) greet[] (d) run greet
  20. 20.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya"));     (a) Hi, name! (b) Riya (c) greet (d) Hi, Riya!
  21. 21.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(20));
  22. 22.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) Zoya (b) Hi, name! (c) greet (d) Hi, Zoya!
  23. 23.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(45, 6));
  24. 24.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 5));
  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(5) + fee(6));
  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 30;
    }
    show(fee(6) + fee(1));
  27. 27.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(85, 4));
  28. 28.🧰 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(10) + fee(1));
  29. 29.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(12));
  30. 30.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(1));
  31. 31.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 2));
  32. 32.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir"));     (a) Well done, Kabir! (b) Kabir (c) Well done, name! (d) greet
  33. 33.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(4));
  34. 34.🧰 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(7));
  35. 35.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(18));
  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 30;
    }
    show(fee(2) + fee(5));
  37. 37.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Kabir"));     (a) Kabir (b) Hi, Kabir! (c) Hi, name! (d) greet
  38. 38.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Meera"));     (a) greet (b) Welcome, name! (c) Welcome, Meera! (d) Meera
  39. 39.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 2));
  40. 40.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir"));     (a) Kabir (b) Welcome, name! (c) greet (d) Welcome, Kabir!

Answer key

  1. Welcome, Arjun!
  2. 90
  3. 18
  4. a named block of code
  5. 70
  6. 40
  7. sends back a value
  8. a parameter
  9. 80
  10. Hello, Kabir!
  11. 50
  12. Hello, Riya!
  13. 32
  14. Well done, Zoya!
  15. 30
  16. 400
  17. 0
  18. 30
  19. greet()
  20. Hi, Riya!
  21. 40
  22. Hi, Zoya!
  23. 270
  24. 275
  25. 60
  26. 30
  27. 340
  28. 20
  29. 24
  30. 40
  31. 110
  32. Well done, Kabir!
  33. 12
  34. 60
  35. 36
  36. 30
  37. Hi, Kabir!
  38. Welcome, Meera!
  39. 120
  40. Welcome, Kabir!

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