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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 448 · 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("Riya"));     (a) greet (b) Welcome, name! (c) Riya (d) Welcome, Riya!
  2. 2.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 5));
  3. 3.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(32));
  4. 4.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) Well done, Arjun! (c) Well done, name! (d) greet
  5. 5.🧰 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(9));
  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 40;
    }
    show(fee(4) + fee(12));
  7. 7.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(40, 4));
  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(4) + fee(2));
  9. 9.🧰 In function tip(bill), what is bill? (a) an event (b) a loop (c) a screen (d) a parameter
  10. 10.🧰 Why write a function? (a) to reuse code (b) to slow the app (c) to hide errors (d) to make code longer
  11. 11.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(37));
  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 60;
    }
    show(fee(7) + fee(1));
  13. 13.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(15));
  14. 14.🧰 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(1) + fee(2));
  15. 15.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(5));
  16. 16.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(0));
  17. 17.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(1));
  18. 18.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(2));
  19. 19.🧰 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(11) + fee(3));
  20. 20.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(3));
  21. 21.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hello, Zoya! (b) greet (c) Hello, name! (d) Zoya
  22. 22.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) Hello, Aman! (b) Hello, name! (c) Aman (d) greet
  23. 23.🧰 What does return do in a function? (a) sends back a value (b) closes the screen (c) repeats the code (d) deletes the app
  24. 24.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 5));
  25. 25.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(2));
  26. 26.🧰 What is a function? (a) a screen size (b) a list of colours (c) a type of phone (d) a named block of code
  27. 27.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 5));
  28. 28.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(15));
  29. 29.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) Welcome, Arjun! (c) greet (d) Welcome, name!
  30. 30.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(19));
  31. 31.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(2));
  32. 32.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) greet (c) Hi, name! (d) Hi, Arjun!
  33. 33.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(5));
  34. 34.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(34));
  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 40;
    }
    show(fee(7) + fee(1));
  36. 36.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) greet (b) Hello, name! (c) Riya (d) Hello, Riya!
  37. 37.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 3));
  38. 38.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(5));
  39. 39.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman"));     (a) Welcome, Aman! (b) Welcome, name! (c) greet (d) Aman
  40. 40.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(75, 5));

Answer key

  1. Welcome, Riya!
  2. 350
  3. 96
  4. Well done, Arjun!
  5. 40
  6. 40
  7. 160
  8. 0
  9. a parameter
  10. to reuse code
  11. 111
  12. 60
  13. 45
  14. 0
  15. 110
  16. 60
  17. 60
  18. 50
  19. 30
  20. 50
  21. Hello, Zoya!
  22. Hello, Aman!
  23. sends back a value
  24. 150
  25. 60
  26. a named block of code
  27. 275
  28. 30
  29. Welcome, Arjun!
  30. 38
  31. 40
  32. Hi, Arjun!
  33. 90
  34. 102
  35. 40
  36. Hello, Riya!
  37. 75
  38. 70
  39. Welcome, Aman!
  40. 375

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