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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 764 · 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(55, 2));
  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 20;
    }
    show(fee(8) + fee(5));
  3. 3.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) Welcome, name! (b) Arjun (c) greet (d) Welcome, Arjun!
  4. 4.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Meera"));     (a) Hello, Meera! (b) greet (c) Meera (d) Hello, name!
  5. 5.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 6));
  6. 6.🧰 What is a function? (a) a screen size (b) a type of phone (c) a list of colours (d) a named block of code
  7. 7.🧰 In function tip(bill), what is bill? (a) a loop (b) a screen (c) a parameter (d) an event
  8. 8.🧰 How do you run (call) a function called greet? (a) run greet (b) greet() (c) greet[] (d) #greet
  9. 9.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(2));
  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 30;
    }
    show(fee(4) + fee(4));
  11. 11.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir"));     (a) Welcome, Kabir! (b) greet (c) Kabir (d) Welcome, name!
  12. 12.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(6));
  13. 13.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(50, 5));
  14. 14.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(21));
  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 40;
    }
    show(fee(4) + fee(9));
  16. 16.🧰 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(4));
  17. 17.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Meera"));     (a) Welcome, name! (b) greet (c) Welcome, Meera! (d) Meera
  18. 18.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(30));
  19. 19.🧰 What does return do in a function? (a) deletes the app (b) repeats the code (c) closes the screen (d) sends back a value
  20. 20.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) Hello, Arjun! (c) greet (d) Hello, name!
  21. 21.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(24));
  22. 22.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(0));
  23. 23.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(31));
  24. 24.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Well done, name! (c) Aman (d) Well done, Aman!
  25. 25.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(4));
  26. 26.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 4));
  27. 27.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(13));
  28. 28.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 4));
  29. 29.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(15));
  30. 30.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(4));
  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 30;
    }
    show(fee(8) + fee(10));
  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(7) + fee(3));
  33. 33.🧰 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(10) + fee(10));
  34. 34.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(0));
  35. 35.🧰 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(5) + fee(6));
  36. 36.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Meera"));     (a) Meera (b) Well done, Meera! (c) greet (d) Well done, name!
  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 30;
    }
    show(fee(1) + fee(6));
  38. 38.🧰 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(1));
  39. 39.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(4));
  40. 40.🧰 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(9));

Answer key

  1. 110
  2. 40
  3. Welcome, Arjun!
  4. Hello, Meera!
  5. 60
  6. a named block of code
  7. a parameter
  8. greet()
  9. 80
  10. 0
  11. Welcome, Kabir!
  12. 18
  13. 250
  14. 42
  15. 40
  16. 0
  17. Welcome, Meera!
  18. 90
  19. sends back a value
  20. Hello, Arjun!
  21. 48
  22. 20
  23. 62
  24. Well done, Aman!
  25. 12
  26. 120
  27. 39
  28. 260
  29. 30
  30. 100
  31. 60
  32. 40
  33. 40
  34. 30
  35. 80
  36. Well done, Meera!
  37. 30
  38. 40
  39. 70
  40. 120

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