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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 722 · 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.🧰 How do you run (call) a function called greet? (a) greet[] (b) run greet (c) #greet (d) greet()
  2. 2.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 2));
  3. 3.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Aman (c) Well done, Aman! (d) Well done, name!
  4. 4.🧰 What does return do in a function? (a) closes the screen (b) deletes the app (c) sends back a value (d) repeats the code
  5. 5.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(34));
  6. 6.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(14));
  7. 7.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(38));
  8. 8.🧰 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));
  9. 9.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hi, name! (b) greet (c) Hi, Kabir! (d) Kabir
  10. 10.🧰 Why write a function? (a) to make code longer (b) to slow the app (c) to reuse code (d) to hide errors
  11. 11.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(27));
  12. 12.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(35));
  13. 13.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 2));
  14. 14.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(40, 2));
  15. 15.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(5));
  16. 16.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(0));
  17. 17.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Zoya (c) Welcome, Zoya! (d) Welcome, name!
  18. 18.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hello, Zoya! (b) greet (c) Zoya (d) Hello, name!
  19. 19.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 6));
  20. 20.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(0));
  21. 21.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hello, name! (b) Kabir (c) Hello, Kabir! (d) greet
  22. 22.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Meera"));     (a) Meera (b) Welcome, Meera! (c) greet (d) Welcome, name!
  23. 23.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Meera"));     (a) Hello, name! (b) Meera (c) Hello, Meera! (d) greet
  24. 24.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) greet (c) Welcome, name! (d) Welcome, Arjun!
  25. 25.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun"));     (a) greet (b) Hello, Arjun! (c) Hello, name! (d) Arjun
  26. 26.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(3));
  27. 27.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) Hello, Aman! (b) Aman (c) Hello, name! (d) greet
  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 50;
    }
    show(fee(12) + fee(4));
  29. 29.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Zoya"));     (a) Well done, name! (b) Zoya (c) greet (d) Well done, Zoya!
  30. 30.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(39));
  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(5) + fee(9));
  32. 32.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 3));
  33. 33.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(50, 2));
  34. 34.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir"));     (a) greet (b) Well done, name! (c) Well done, Kabir! (d) Kabir
  35. 35.🧰 What is a function? (a) a list of colours (b) a screen size (c) a named block of code (d) a type of phone
  36. 36.🧰 In function tip(bill), what is bill? (a) an event (b) a loop (c) a screen (d) a parameter
  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(7) + fee(5));
  38. 38.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(15));
  39. 39.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(5));
  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 50;
    }
    show(fee(8) + fee(1));

Answer key

  1. greet()
  2. 160
  3. Well done, Aman!
  4. sends back a value
  5. 68
  6. 28
  7. 76
  8. 60
  9. Hi, Kabir!
  10. to reuse code
  11. 54
  12. 70
  13. 120
  14. 80
  15. 80
  16. 40
  17. Welcome, Zoya!
  18. Hello, Zoya!
  19. 420
  20. 60
  21. Hello, Kabir!
  22. Welcome, Meera!
  23. Hello, Meera!
  24. Welcome, Arjun!
  25. Hello, Arjun!
  26. 6
  27. Hello, Aman!
  28. 50
  29. Well done, Zoya!
  30. 117
  31. 40
  32. 240
  33. 100
  34. Well done, Kabir!
  35. a named block of code
  36. a parameter
  37. 60
  38. 30
  39. 10
  40. 50

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