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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 133 · 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.🧰 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(3) + fee(8));
  2. 2.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(3));
  3. 3.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(2));
  4. 4.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(90, 3));
  5. 5.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Meera"));     (a) greet (b) Well done, Meera! (c) Meera (d) Well done, name!
  6. 6.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 3));
  7. 7.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(0));
  8. 8.🧰 How do you run (call) a function called greet? (a) #greet (b) greet() (c) greet[] (d) run greet
  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(2) + fee(5));
  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 40;
    }
    show(fee(11) + fee(7));
  11. 11.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 3));
  12. 12.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(1));
  13. 13.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) Aman (b) Hello, name! (c) greet (d) Hello, Aman!
  14. 14.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 5));
  15. 15.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 6));
  16. 16.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(18));
  17. 17.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 4));
  18. 18.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 3));
  19. 19.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 2));
  20. 20.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 5));
  21. 21.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(0));
  22. 22.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(12));
  23. 23.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) greet (c) Welcome, Arjun! (d) Welcome, name!
  24. 24.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) greet (b) Arjun (c) Well done, name! (d) Well done, Arjun!
  25. 25.🧰 In function tip(bill), what is bill? (a) an event (b) a screen (c) a loop (d) a parameter
  26. 26.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(50, 6));
  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(5) + fee(7));
  28. 28.🧰 Why write a function? (a) to make code longer (b) to slow the app (c) to hide errors (d) to reuse code
  29. 29.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(23));
  30. 30.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(17));
  31. 31.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 4));
  32. 32.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Hi, name! (c) Hi, Aman! (d) Aman
  33. 33.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya"));     (a) greet (b) Riya (c) Hi, Riya! (d) Hi, name!
  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(10) + fee(12));
  35. 35.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(39));
  36. 36.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Well done, Riya! (b) Riya (c) Well done, name! (d) greet
  37. 37.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) Hello, name! (b) Riya (c) greet (d) Hello, Riya!
  38. 38.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(40, 3));
  39. 39.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(3));
  40. 40.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Kabir"));     (a) greet (b) Kabir (c) Hi, Kabir! (d) Hi, name!

Answer key

  1. 50
  2. 50
  3. 80
  4. 270
  5. Well done, Meera!
  6. 210
  7. 40
  8. greet()
  9. 60
  10. 80
  11. 165
  12. 70
  13. Hello, Aman!
  14. 100
  15. 210
  16. 36
  17. 100
  18. 90
  19. 20
  20. 300
  21. 50
  22. 36
  23. Welcome, Arjun!
  24. Well done, Arjun!
  25. a parameter
  26. 300
  27. 60
  28. to reuse code
  29. 69
  30. 34
  31. 140
  32. Hi, Aman!
  33. Hi, Riya!
  34. 100
  35. 117
  36. Well done, Riya!
  37. Hello, Riya!
  38. 120
  39. 6
  40. Hi, Kabir!

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