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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 692 · 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 "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) Zoya (b) Hello, name! (c) greet (d) Hello, Zoya!
  2. 2.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(75, 3));
  3. 3.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(0));
  4. 4.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) Well done, Arjun! (b) greet (c) Arjun (d) Well done, name!
  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(12) + fee(6));
  6. 6.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(0));
  7. 7.🧰 In function tip(bill), what is bill? (a) a parameter (b) an event (c) a screen (d) a loop
  8. 8.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(85, 2));
  9. 9.🧰 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(12) + fee(12));
  10. 10.🧰 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(2));
  11. 11.🧰 How do you run (call) a function called greet? (a) greet() (b) greet[] (c) run greet (d) #greet
  12. 12.🧰 What does return do in a function? (a) repeats the code (b) deletes the app (c) sends back a value (d) closes the screen
  13. 13.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Meera"));     (a) Welcome, Meera! (b) Meera (c) greet (d) Welcome, name!
  14. 14.🧰 What is a function? (a) a list of colours (b) a named block of code (c) a screen size (d) a type of phone
  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 50;
    }
    show(fee(12) + fee(10));
  16. 16.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(5));
  17. 17.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(31));
  18. 18.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Meera"));     (a) greet (b) Hi, Meera! (c) Meera (d) Hi, name!
  19. 19.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(45, 4));
  20. 20.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(1));
  21. 21.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 5));
  22. 22.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(23));
  23. 23.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Riya"));     (a) Welcome, name! (b) Riya (c) Welcome, Riya! (d) greet
  24. 24.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Aman"));     (a) Well done, Aman! (b) Aman (c) Well done, name! (d) greet
  25. 25.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(5));
  26. 26.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(16));
  27. 27.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(4));
  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 60;
    }
    show(fee(8) + fee(5));
  29. 29.🧰 Why write a function? (a) to make code longer (b) to slow the app (c) to reuse code (d) to hide errors
  30. 30.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(2));
  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(4) + fee(7));
  32. 32.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(3));
  33. 33.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir"));     (a) Well done, name! (b) Well done, Kabir! (c) greet (d) Kabir
  34. 34.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(5));
  35. 35.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 6));
  36. 36.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 2));
  37. 37.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(90, 3));
  38. 38.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(39));
  39. 39.🧰 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));
  40. 40.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(33));

Answer key

  1. Hello, Zoya!
  2. 225
  3. 20
  4. Well done, Arjun!
  5. 40
  6. 60
  7. a parameter
  8. 170
  9. 120
  10. 20
  11. greet()
  12. sends back a value
  13. Welcome, Meera!
  14. a named block of code
  15. 100
  16. 100
  17. 62
  18. Hi, Meera!
  19. 180
  20. 60
  21. 175
  22. 69
  23. Welcome, Riya!
  24. Well done, Aman!
  25. 15
  26. 32
  27. 100
  28. 120
  29. to reuse code
  30. 70
  31. 20
  32. 70
  33. Well done, Kabir!
  34. 110
  35. 480
  36. 30
  37. 270
  38. 78
  39. 40
  40. 66

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