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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 894 · 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.🧰 Why write a function? (a) to slow the app (b) to make code longer (c) to hide errors (d) to reuse code
  2. 2.🧰 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(3));
  3. 3.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 5));
  4. 4.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(0));
  5. 5.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(85, 2));
  6. 6.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Well done, Aman! (c) Aman (d) Well done, name!
  7. 7.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(27));
  8. 8.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 3));
  9. 9.🧰 What is a function? (a) a named block of code (b) a screen size (c) a list of colours (d) a type of phone
  10. 10.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) Welcome, Arjun! (b) Welcome, name! (c) Arjun (d) greet
  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 60;
    }
    show(fee(10) + fee(10));
  12. 12.🧰 In function tip(bill), what is bill? (a) a parameter (b) a loop (c) a screen (d) an event
  13. 13.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(0));
  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 20;
    }
    show(fee(11) + fee(6));
  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 60;
    }
    show(fee(6) + fee(8));
  16. 16.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(34));
  17. 17.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) greet (b) Hello, name! (c) Hello, Riya! (d) Riya
  18. 18.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(3));
  19. 19.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Zoya"));     (a) Welcome, name! (b) Zoya (c) greet (d) Welcome, Zoya!
  20. 20.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman"));     (a) Hi, name! (b) Hi, Aman! (c) greet (d) Aman
  21. 21.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(40));
  22. 22.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 4));
  23. 23.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) Zoya (b) Hi, Zoya! (c) greet (d) Hi, name!
  24. 24.🧰 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(12));
  25. 25.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(28));
  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 50;
    }
    show(fee(11) + fee(8));
  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 20;
    }
    show(fee(1) + fee(9));
  28. 28.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(15));
  29. 29.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(4));
  30. 30.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(11));
  31. 31.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) Hello, Arjun! (c) Hello, name! (d) greet
  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 40;
    }
    show(fee(9) + fee(1));
  33. 33.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 2));
  34. 34.🧰 How do you run (call) a function called greet? (a) greet() (b) run greet (c) #greet (d) greet[]
  35. 35.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Meera"));     (a) greet (b) Well done, name! (c) Well done, Meera! (d) Meera
  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 40;
    }
    show(fee(11) + fee(1));
  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 20;
    }
    show(fee(4) + fee(9));
  38. 38.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(23));
  39. 39.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(40, 2));
  40. 40.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(31));

Answer key

  1. to reuse code
  2. 0
  3. 400
  4. 40
  5. 170
  6. Well done, Aman!
  7. 54
  8. 90
  9. a named block of code
  10. Welcome, Arjun!
  11. 120
  12. a parameter
  13. 60
  14. 40
  15. 120
  16. 68
  17. Hello, Riya!
  18. 9
  19. Welcome, Zoya!
  20. Hi, Aman!
  21. 120
  22. 100
  23. Hi, Zoya!
  24. 30
  25. 56
  26. 100
  27. 20
  28. 30
  29. 8
  30. 22
  31. Hello, Arjun!
  32. 40
  33. 110
  34. greet()
  35. Well done, Meera!
  36. 40
  37. 20
  38. 46
  39. 80
  40. 62

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