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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 238 · 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.🧰 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(12));
  2. 2.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman"));     (a) Hi, name! (b) Aman (c) greet (d) Hi, Aman!
  3. 3.🧰 What is a function? (a) a type of phone (b) a list of colours (c) a screen size (d) a named block of code
  4. 4.🧰 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(5));
  5. 5.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(1));
  6. 6.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Zoya"));     (a) Zoya (b) Welcome, Zoya! (c) Welcome, name! (d) greet
  7. 7.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(4));
  8. 8.🧰 How do you run (call) a function called greet? (a) run greet (b) greet[] (c) #greet (d) greet()
  9. 9.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman"));     (a) Welcome, name! (b) Aman (c) greet (d) Welcome, Aman!
  10. 10.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 6));
  11. 11.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(3));
  12. 12.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(9));
  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 30;
    }
    show(fee(3) + fee(8));
  14. 14.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 4));
  15. 15.🧰 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));
  16. 16.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) Hello, Aman! (b) Hello, name! (c) greet (d) Aman
  17. 17.🧰 Why write a function? (a) to slow the app (b) to reuse code (c) to make code longer (d) to hide errors
  18. 18.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(40, 2));
  19. 19.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) Well done, name! (b) Arjun (c) greet (d) Well done, Arjun!
  20. 20.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(3));
  21. 21.🧰 What does return do in a function? (a) sends back a value (b) deletes the app (c) closes the screen (d) repeats the code
  22. 22.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 6));
  23. 23.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 4));
  24. 24.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(28));
  25. 25.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Meera"));     (a) Hi, name! (b) Hi, Meera! (c) greet (d) Meera
  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 20;
    }
    show(fee(12) + fee(11));
  27. 27.🧰 In function tip(bill), what is bill? (a) an event (b) a parameter (c) a screen (d) a loop
  28. 28.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(1));
  29. 29.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Meera"));     (a) Well done, Meera! (b) greet (c) Well done, name! (d) Meera
  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 total(price, qty) {
      return price * qty;
    }
    show(total(20, 6));
  32. 32.🧰 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(5) + fee(8));
  33. 33.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(5));
  34. 34.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Zoya"));     (a) Well done, Zoya! (b) Well done, name! (c) Zoya (d) greet
  35. 35.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(75, 4));
  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 60;
    }
    show(fee(7) + fee(5));
  37. 37.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(2));
  38. 38.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(0));
  39. 39.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(29));
  40. 40.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(8));

Answer key

  1. 50
  2. Hi, Aman!
  3. a named block of code
  4. 80
  5. 70
  6. Welcome, Zoya!
  7. 70
  8. greet()
  9. Welcome, Aman!
  10. 210
  11. 80
  12. 18
  13. 30
  14. 260
  15. 60
  16. Hello, Aman!
  17. to reuse code
  18. 80
  19. Well done, Arjun!
  20. 9
  21. sends back a value
  22. 180
  23. 60
  24. 56
  25. Hi, Meera!
  26. 40
  27. a parameter
  28. 30
  29. Well done, Meera!
  30. 38
  31. 120
  32. 120
  33. 80
  34. Well done, Zoya!
  35. 300
  36. 120
  37. 80
  38. 20
  39. 87
  40. 24

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