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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 253 · 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 double(n) {
      return n * 2;
    }
    show(double(34));
  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(4) + fee(4));
  3. 3.🧰 What does return do in a function? (a) deletes the app (b) sends back a value (c) closes the screen (d) repeats the code
  4. 4.🧰 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(7) + fee(9));
  5. 5.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(1));
  6. 6.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(0));
  7. 7.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(15));
  8. 8.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(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(7) + fee(1));
  10. 10.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Zoya"));     (a) Zoya (b) Welcome, name! (c) Welcome, Zoya! (d) greet
  11. 11.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 4));
  12. 12.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Aman"));     (a) Well done, name! (b) Well done, Aman! (c) Aman (d) greet
  13. 13.🧰 How do you run (call) a function called greet? (a) greet() (b) run greet (c) greet[] (d) #greet
  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 40;
    }
    show(fee(6) + fee(2));
  15. 15.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(5));
  16. 16.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 3));
  17. 17.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(2));
  18. 18.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(40));
  19. 19.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya"));     (a) greet (b) Hi, name! (c) Hi, Riya! (d) Riya
  20. 20.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(33));
  21. 21.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(30));
  22. 22.🧰 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(2) + fee(1));
  23. 23.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) Hello, name! (b) Hello, Riya! (c) greet (d) Riya
  24. 24.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(3));
  25. 25.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(29));
  26. 26.🧰 Why write a function? (a) to hide errors (b) to slow the app (c) to reuse code (d) to make code longer
  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 30;
    }
    show(fee(6) + fee(1));
  28. 28.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) greet (b) Well done, Riya! (c) Riya (d) Well done, name!
  29. 29.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(32));
  30. 30.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(2));
  31. 31.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(5));
  32. 32.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(34));
  33. 33.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(5));
  34. 34.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 6));
  35. 35.🧰 What is a function? (a) a named block of code (b) a list of colours (c) a screen size (d) a type of phone
  36. 36.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(2));
  37. 37.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) Kabir (b) greet (c) Hello, name! (d) Hello, Kabir!
  38. 38.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 5));
  39. 39.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Meera"));     (a) Hello, name! (b) Meera (c) Hello, Meera! (d) greet
  40. 40.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Meera"));     (a) Meera (b) greet (c) Welcome, Meera! (d) Welcome, name!

Answer key

  1. 68
  2. 0
  3. sends back a value
  4. 120
  5. 70
  6. 50
  7. 45
  8. 80
  9. 60
  10. Welcome, Zoya!
  11. 280
  12. Well done, Aman!
  13. greet()
  14. 40
  15. 110
  16. 30
  17. 60
  18. 120
  19. Hi, Riya!
  20. 99
  21. 90
  22. 0
  23. Hello, Riya!
  24. 9
  25. 87
  26. to reuse code
  27. 30
  28. Well done, Riya!
  29. 96
  30. 40
  31. 70
  32. 102
  33. 90
  34. 480
  35. a named block of code
  36. 70
  37. Hello, Kabir!
  38. 125
  39. Hello, Meera!
  40. Welcome, Meera!

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