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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 174 · 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(50, 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 40;
    }
    show(fee(9) + fee(12));
  3. 3.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(40, 3));
  4. 4.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(5));
  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 30;
    }
    show(fee(10) + fee(12));
  6. 6.🧰 What is a function? (a) a list of colours (b) a screen size (c) a named block of code (d) a type of phone
  7. 7.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir"));     (a) Kabir (b) Welcome, name! (c) greet (d) Welcome, Kabir!
  8. 8.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun"));     (a) Hello, Arjun! (b) Hello, name! (c) greet (d) Arjun
  9. 9.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(13));
  10. 10.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 3));
  11. 11.🧰 Why write a function? (a) to slow the app (b) to reuse code (c) to make code longer (d) to hide errors
  12. 12.🧰 What does return do in a function? (a) sends back a value (b) repeats the code (c) closes the screen (d) deletes the app
  13. 13.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) greet (b) Kabir (c) Hello, Kabir! (d) Hello, name!
  14. 14.🧰 How do you run (call) a function called greet? (a) greet[] (b) #greet (c) greet() (d) run greet
  15. 15.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(12));
  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(1) + fee(6));
  17. 17.🧰 In function tip(bill), what is bill? (a) a screen (b) an event (c) a parameter (d) a loop
  18. 18.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(36));
  19. 19.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(5));
  20. 20.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Arjun"));     (a) Hi, Arjun! (b) greet (c) Arjun (d) Hi, name!
  21. 21.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(14));
  22. 22.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman"));     (a) Aman (b) Hi, Aman! (c) greet (d) Hi, name!
  23. 23.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(11));
  24. 24.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(3));
  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 50;
    }
    show(fee(10) + fee(4));
  26. 26.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Aman (c) Hello, name! (d) Hello, Aman!
  27. 27.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 5));
  28. 28.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(3));
  29. 29.🧰 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(8) + fee(6));
  30. 30.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) greet (b) Welcome, name! (c) Welcome, Arjun! (d) Arjun
  31. 31.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 6));
  32. 32.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(19));
  33. 33.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(40));
  34. 34.🧰 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(6) + fee(5));
  35. 35.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Meera"));     (a) greet (b) Hello, Meera! (c) Meera (d) Hello, name!
  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 30;
    }
    show(fee(12) + fee(6));
  37. 37.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(5));
  38. 38.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman"));     (a) Welcome, name! (b) Aman (c) greet (d) Welcome, Aman!
  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 30;
    }
    show(fee(12) + fee(12));
  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 30;
    }
    show(fee(12) + fee(11));

Answer key

  1. 100
  2. 80
  3. 120
  4. 100
  5. 60
  6. a named block of code
  7. Welcome, Kabir!
  8. Hello, Arjun!
  9. 39
  10. 195
  11. to reuse code
  12. sends back a value
  13. Hello, Kabir!
  14. greet()
  15. 24
  16. 30
  17. a parameter
  18. 108
  19. 15
  20. Hi, Arjun!
  21. 28
  22. Hi, Aman!
  23. 22
  24. 70
  25. 50
  26. Hello, Aman!
  27. 275
  28. 80
  29. 100
  30. Welcome, Arjun!
  31. 90
  32. 38
  33. 120
  34. 100
  35. Hello, Meera!
  36. 60
  37. 70
  38. Welcome, Aman!
  39. 60
  40. 60

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