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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 928 · 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 "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Hi, name! (c) Zoya (d) Hi, Zoya!
  2. 2.🧰 What is a function? (a) a list of colours (b) a named block of code (c) a type of phone (d) a screen size
  3. 3.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hello, name! (b) Zoya (c) greet (d) Hello, Zoya!
  4. 4.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(2));
  5. 5.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 2));
  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 60;
    }
    show(fee(10) + fee(11));
  7. 7.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Zoya"));     (a) Welcome, name! (b) greet (c) Zoya (d) Welcome, Zoya!
  8. 8.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(1));
  9. 9.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 2));
  10. 10.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 5));
  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 20;
    }
    show(fee(11) + fee(5));
  12. 12.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Meera"));     (a) Welcome, name! (b) Meera (c) Welcome, Meera! (d) greet
  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(6) + fee(9));
  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 30;
    }
    show(fee(10) + fee(2));
  15. 15.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(4));
  16. 16.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Aman (c) Hello, Aman! (d) Hello, name!
  17. 17.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Meera"));     (a) Well done, name! (b) greet (c) Meera (d) Well done, Meera!
  18. 18.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Arjun"));     (a) Hi, name! (b) Hi, Arjun! (c) greet (d) Arjun
  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 60;
    }
    show(fee(2) + fee(2));
  20. 20.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(19));
  21. 21.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(14));
  22. 22.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(28));
  23. 23.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(8));
  24. 24.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(1));
  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 60;
    }
    show(fee(2) + fee(8));
  26. 26.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 2));
  27. 27.🧰 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(3) + fee(11));
  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 50;
    }
    show(fee(4) + fee(10));
  29. 29.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir"));     (a) Welcome, Kabir! (b) Kabir (c) Welcome, name! (d) greet
  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 30;
    }
    show(fee(10) + fee(7));
  31. 31.🧰 Why write a function? (a) to reuse code (b) to hide errors (c) to slow the app (d) to make code longer
  32. 32.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) greet (b) Arjun (c) Welcome, name! (d) Welcome, Arjun!
  33. 33.🧰 In function tip(bill), what is bill? (a) a screen (b) a loop (c) a parameter (d) an event
  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(9) + fee(2));
  35. 35.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 3));
  36. 36.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(39));
  37. 37.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(5));
  38. 38.🧰 What does return do in a function? (a) sends back a value (b) deletes the app (c) repeats the code (d) closes the screen
  39. 39.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 3));
  40. 40.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 3));

Answer key

  1. Hi, Zoya!
  2. a named block of code
  3. Hello, Zoya!
  4. 70
  5. 130
  6. 120
  7. Welcome, Zoya!
  8. 60
  9. 160
  10. 300
  11. 40
  12. Welcome, Meera!
  13. 100
  14. 30
  15. 100
  16. Hello, Aman!
  17. Well done, Meera!
  18. Hi, Arjun!
  19. 0
  20. 38
  21. 42
  22. 56
  23. 16
  24. 30
  25. 60
  26. 70
  27. 50
  28. 50
  29. Welcome, Kabir!
  30. 60
  31. to reuse code
  32. Welcome, Arjun!
  33. a parameter
  34. 30
  35. 90
  36. 117
  37. 80
  38. sends back a value
  39. 285
  40. 240

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