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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 748 · 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 20;
    }
    show(fee(1) + fee(5));
  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 40;
    }
    show(fee(1) + fee(1));
  3. 3.🧰 In function tip(bill), what is bill? (a) an event (b) a screen (c) a parameter (d) a loop
  4. 4.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hi, Kabir! (b) Kabir (c) greet (d) Hi, name!
  5. 5.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(4));
  6. 6.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(1));
  7. 7.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) Well done, name! (b) Well done, Arjun! (c) Arjun (d) greet
  8. 8.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Zoya"));     (a) Well done, name! (b) greet (c) Zoya (d) Well done, Zoya!
  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 40;
    }
    show(fee(11) + fee(2));
  10. 10.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(37));
  11. 11.🧰 What is a function? (a) a named block of code (b) a screen size (c) a type of phone (d) a list of colours
  12. 12.🧰 How do you run (call) a function called greet? (a) run greet (b) greet() (c) greet[] (d) #greet
  13. 13.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 5));
  14. 14.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Meera"));     (a) Hi, name! (b) Hi, Meera! (c) Meera (d) greet
  15. 15.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Aman"));     (a) Well done, name! (b) Well done, Aman! (c) greet (d) Aman
  16. 16.🧰 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(7));
  17. 17.🧰 Why write a function? (a) to slow the app (b) to reuse code (c) to make code longer (d) to hide errors
  18. 18.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(5));
  19. 19.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(17));
  20. 20.🧰 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(4) + fee(9));
  21. 21.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(30));
  22. 22.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(1));
  23. 23.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(85, 4));
  24. 24.🧰 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(9));
  25. 25.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(4));
  26. 26.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 5));
  27. 27.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman"));     (a) Aman (b) Hi, name! (c) greet (d) Hi, Aman!
  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 40;
    }
    show(fee(3) + fee(7));
  29. 29.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(1));
  30. 30.🧰 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(4) + fee(8));
  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 50;
    }
    show(fee(4) + fee(7));
  32. 32.🧰 What does return do in a function? (a) repeats the code (b) deletes the app (c) closes the screen (d) sends back a value
  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 30;
    }
    show(fee(11) + fee(2));
  34. 34.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(39));
  35. 35.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(35));
  36. 36.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(19));
  37. 37.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 6));
  38. 38.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Riya"));     (a) Riya (b) Welcome, name! (c) Welcome, Riya! (d) greet
  39. 39.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(18));
  40. 40.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 2));

Answer key

  1. 20
  2. 0
  3. a parameter
  4. Hi, Kabir!
  5. 12
  6. 50
  7. Well done, Arjun!
  8. Well done, Zoya!
  9. 40
  10. 111
  11. a named block of code
  12. greet()
  13. 275
  14. Hi, Meera!
  15. Well done, Aman!
  16. 60
  17. to reuse code
  18. 80
  19. 51
  20. 30
  21. 60
  22. 30
  23. 340
  24. 60
  25. 60
  26. 150
  27. Hi, Aman!
  28. 40
  29. 70
  30. 50
  31. 50
  32. sends back a value
  33. 30
  34. 117
  35. 105
  36. 38
  37. 480
  38. Welcome, Riya!
  39. 36
  40. 110

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