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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 169 · 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 number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 5));
  2. 2.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(15));
  3. 3.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Well done, name! (b) Riya (c) Well done, Riya! (d) greet
  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 50;
    }
    show(fee(3) + fee(1));
  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 40;
    }
    show(fee(8) + fee(11));
  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(7) + fee(6));
  7. 7.🧰 What does return do in a function? (a) deletes the app (b) repeats the code (c) closes the screen (d) sends back a value
  8. 8.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 5));
  9. 9.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(50, 2));
  10. 10.🧰 Why write a function? (a) to slow the app (b) to make code longer (c) to hide errors (d) to reuse code
  11. 11.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(40));
  12. 12.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(90, 2));
  13. 13.🧰 How do you run (call) a function called greet? (a) #greet (b) greet() (c) greet[] (d) run greet
  14. 14.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(85, 2));
  15. 15.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 3));
  16. 16.🧰 What is a function? (a) a list of colours (b) a screen size (c) a type of phone (d) a named block of code
  17. 17.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(50, 3));
  18. 18.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(0));
  19. 19.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) Zoya (b) greet (c) Hello, Zoya! (d) Hello, name!
  20. 20.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(39));
  21. 21.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) Well done, name! (b) Well done, Arjun! (c) greet (d) Arjun
  22. 22.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Meera"));     (a) Welcome, Meera! (b) Welcome, name! (c) Meera (d) greet
  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 30;
    }
    show(fee(3) + fee(1));
  24. 24.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(50, 4));
  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 40;
    }
    show(fee(10) + fee(11));
  26. 26.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 5));
  27. 27.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(30));
  28. 28.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(3));
  29. 29.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(4));
  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 20;
    }
    show(fee(5) + fee(12));
  31. 31.🧰 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(7) + fee(9));
  32. 32.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) Welcome, name! (b) greet (c) Welcome, Arjun! (d) Arjun
  33. 33.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(6));
  34. 34.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Meera"));     (a) Hello, Meera! (b) Hello, name! (c) greet (d) Meera
  35. 35.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(1));
  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(5) + fee(6));
  37. 37.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman"));     (a) Hi, name! (b) Aman (c) greet (d) Hi, Aman!
  38. 38.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 2));
  39. 39.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Riya"));     (a) Welcome, Riya! (b) greet (c) Welcome, name! (d) Riya
  40. 40.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) Riya (b) Hello, name! (c) Hello, Riya! (d) greet

Answer key

  1. 50
  2. 30
  3. Well done, Riya!
  4. 0
  5. 80
  6. 40
  7. sends back a value
  8. 475
  9. 100
  10. to reuse code
  11. 80
  12. 180
  13. greet()
  14. 170
  15. 300
  16. a named block of code
  17. 150
  18. 50
  19. Hello, Zoya!
  20. 78
  21. Well done, Arjun!
  22. Welcome, Meera!
  23. 0
  24. 200
  25. 80
  26. 350
  27. 60
  28. 80
  29. 60
  30. 40
  31. 40
  32. Welcome, Arjun!
  33. 18
  34. Hello, Meera!
  35. 50
  36. 120
  37. Hi, Aman!
  38. 50
  39. Welcome, Riya!
  40. Hello, Riya!

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