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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 60 · 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 is a function? (a) a type of phone (b) a screen size (c) a named block of code (d) a list of colours
  2. 2.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(1));
  3. 3.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 2));
  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 40;
    }
    show(fee(12) + fee(3));
  5. 5.🧰 How do you run (call) a function called greet? (a) #greet (b) greet[] (c) run greet (d) greet()
  6. 6.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya"));     (a) Hi, Riya! (b) greet (c) Hi, name! (d) Riya
  7. 7.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Meera"));     (a) greet (b) Meera (c) Hi, Meera! (d) Hi, name!
  8. 8.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(90, 6));
  9. 9.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 4));
  10. 10.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Welcome, name! (c) Aman (d) Welcome, Aman!
  11. 11.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(1));
  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 40;
    }
    show(fee(12) + fee(9));
  13. 13.🧰 Why write a function? (a) to make code longer (b) to hide errors (c) to reuse code (d) to slow the app
  14. 14.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir"));     (a) greet (b) Kabir (c) Well done, Kabir! (d) Well done, name!
  15. 15.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(35));
  16. 16.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 5));
  17. 17.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(1));
  18. 18.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Arjun"));     (a) greet (b) Hi, name! (c) Hi, Arjun! (d) Arjun
  19. 19.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 5));
  20. 20.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 5));
  21. 21.🧰 What does return do in a function? (a) repeats the code (b) deletes the app (c) closes the screen (d) sends back a value
  22. 22.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir"));     (a) greet (b) Welcome, name! (c) Kabir (d) Welcome, Kabir!
  23. 23.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 3));
  24. 24.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(5));
  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 40;
    }
    show(fee(1) + fee(8));
  26. 26.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(24));
  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 50;
    }
    show(fee(2) + fee(11));
  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 20;
    }
    show(fee(2) + fee(11));
  29. 29.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(2));
  30. 30.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Well done, name! (b) Well done, Riya! (c) greet (d) Riya
  31. 31.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 5));
  32. 32.🧰 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(9));
  33. 33.🧰 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(1) + fee(8));
  34. 34.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(39));
  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 60;
    }
    show(fee(8) + fee(3));
  36. 36.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(85, 2));
  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 40;
    }
    show(fee(10) + fee(6));
  38. 38.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(13));
  39. 39.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(0));
  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(9) + fee(9));

Answer key

  1. a named block of code
  2. 30
  3. 50
  4. 40
  5. greet()
  6. Hi, Riya!
  7. Hi, Meera!
  8. 540
  9. 380
  10. Welcome, Aman!
  11. 50
  12. 80
  13. to reuse code
  14. Well done, Kabir!
  15. 105
  16. 275
  17. 60
  18. Hi, Arjun!
  19. 500
  20. 325
  21. sends back a value
  22. Welcome, Kabir!
  23. 45
  24. 70
  25. 40
  26. 48
  27. 50
  28. 20
  29. 80
  30. Well done, Riya!
  31. 300
  32. 60
  33. 60
  34. 78
  35. 60
  36. 170
  37. 80
  38. 26
  39. 50
  40. 100

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