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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 814 · 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(95, 4));
  2. 2.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(26));
  3. 3.🧰 In function tip(bill), what is bill? (a) a screen (b) a parameter (c) an event (d) a loop
  4. 4.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(3));
  5. 5.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(31));
  6. 6.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(4));
  7. 7.🧰 Why write a function? (a) to reuse code (b) to slow the app (c) to hide errors (d) to make code longer
  8. 8.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 2));
  9. 9.🧰 What does return do in a function? (a) closes the screen (b) deletes the app (c) repeats the code (d) sends back a value
  10. 10.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(4));
  11. 11.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(3));
  12. 12.🧰 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(3));
  13. 13.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Aman"));     (a) Aman (b) greet (c) Well done, Aman! (d) Well done, name!
  14. 14.🧰 How do you run (call) a function called greet? (a) greet[] (b) run greet (c) greet() (d) #greet
  15. 15.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(2));
  16. 16.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(10));
  17. 17.🧰 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(4));
  18. 18.🧰 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(12));
  19. 19.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) Riya (b) Hello, name! (c) Hello, Riya! (d) greet
  20. 20.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 3));
  21. 21.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hi, name! (b) Kabir (c) Hi, Kabir! (d) greet
  22. 22.🧰 What is a function? (a) a type of phone (b) a list of colours (c) a screen size (d) a named block of code
  23. 23.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(2));
  24. 24.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(4));
  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 20;
    }
    show(fee(12) + fee(5));
  26. 26.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(23));
  27. 27.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(0));
  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 30;
    }
    show(fee(1) + fee(2));
  29. 29.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(45, 4));
  30. 30.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hello, Zoya! (b) greet (c) Zoya (d) Hello, name!
  31. 31.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(6));
  32. 32.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 3));
  33. 33.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Well done, name! (b) Riya (c) Well done, Riya! (d) greet
  34. 34.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(90, 3));
  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 50;
    }
    show(fee(6) + fee(6));
  36. 36.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(4));
  37. 37.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 3));
  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 50;
    }
    show(fee(8) + fee(4));
  39. 39.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(50, 2));
  40. 40.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir"));     (a) greet (b) Welcome, Kabir! (c) Kabir (d) Welcome, name!

Answer key

  1. 380
  2. 78
  3. a parameter
  4. 50
  5. 93
  6. 80
  7. to reuse code
  8. 160
  9. sends back a value
  10. 90
  11. 80
  12. 20
  13. Well done, Aman!
  14. greet()
  15. 80
  16. 20
  17. 40
  18. 40
  19. Hello, Riya!
  20. 180
  21. Hi, Kabir!
  22. a named block of code
  23. 50
  24. 70
  25. 40
  26. 69
  27. 20
  28. 0
  29. 180
  30. Hello, Zoya!
  31. 12
  32. 165
  33. Well done, Riya!
  34. 270
  35. 100
  36. 12
  37. 300
  38. 50
  39. 100
  40. Welcome, Kabir!

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