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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 295 · 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.🧰 How do you run (call) a function called greet? (a) greet[] (b) run greet (c) #greet (d) greet()
  2. 2.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 5));
  3. 3.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(1));
  4. 4.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(0));
  5. 5.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(10));
  6. 6.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) Welcome, Arjun! (b) Arjun (c) greet (d) Welcome, name!
  7. 7.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(16));
  8. 8.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 6));
  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 40;
    }
    show(fee(6) + fee(8));
  10. 10.🧰 What is a function? (a) a type of phone (b) a list of colours (c) a named block of code (d) a screen size
  11. 11.🧰 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(4));
  12. 12.🧰 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(8));
  13. 13.🧰 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(1));
  14. 14.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Hi, name! (c) Zoya (d) Hi, Zoya!
  15. 15.🧰 In function tip(bill), what is bill? (a) a screen (b) an event (c) a parameter (d) a loop
  16. 16.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 6));
  17. 17.🧰 Why write a function? (a) to slow the app (b) to make code longer (c) to reuse code (d) to hide errors
  18. 18.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) Well done, Arjun! (b) Well done, name! (c) Arjun (d) greet
  19. 19.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hi, name! (b) Kabir (c) Hi, Kabir! (d) greet
  20. 20.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(6));
  21. 21.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 6));
  22. 22.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(4));
  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 20;
    }
    show(fee(1) + fee(9));
  24. 24.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 2));
  25. 25.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Well done, name! (b) greet (c) Riya (d) Well done, Riya!
  26. 26.🧰 What does return do in a function? (a) deletes the app (b) closes the screen (c) sends back a value (d) repeats the code
  27. 27.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(0));
  28. 28.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(1));
  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 60;
    }
    show(fee(12) + fee(12));
  30. 30.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(21));
  31. 31.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(3));
  32. 32.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(3));
  33. 33.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Meera"));     (a) Welcome, Meera! (b) Welcome, name! (c) greet (d) Meera
  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 20;
    }
    show(fee(4) + fee(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(4));
  36. 36.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(14));
  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 30;
    }
    show(fee(9) + fee(4));
  38. 38.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(3));
  39. 39.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Zoya"));     (a) Zoya (b) Well done, name! (c) greet (d) Well done, Zoya!
  40. 40.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 3));

Answer key

  1. greet()
  2. 100
  3. 30
  4. 60
  5. 30
  6. Welcome, Arjun!
  7. 32
  8. 420
  9. 80
  10. a named block of code
  11. 0
  12. 30
  13. 50
  14. Hi, Zoya!
  15. a parameter
  16. 180
  17. to reuse code
  18. Well done, Arjun!
  19. Hi, Kabir!
  20. 18
  21. 360
  22. 60
  23. 20
  24. 120
  25. Well done, Riya!
  26. sends back a value
  27. 30
  28. 60
  29. 120
  30. 42
  31. 80
  32. 90
  33. Welcome, Meera!
  34. 20
  35. 60
  36. 28
  37. 30
  38. 6
  39. Well done, Zoya!
  40. 30

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