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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 568 · 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 30;
    }
    show(fee(1) + fee(5));
  2. 2.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(13));
  3. 3.🧰 How do you run (call) a function called greet? (a) greet[] (b) run greet (c) greet() (d) #greet
  4. 4.🧰 Why write a function? (a) to slow the app (b) to reuse code (c) to make code longer (d) to hide errors
  5. 5.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(4));
  6. 6.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya"));     (a) Hi, name! (b) Hi, Riya! (c) greet (d) Riya
  7. 7.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Riya (b) Well done, name! (c) Well done, Riya! (d) greet
  8. 8.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 5));
  9. 9.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(35));
  10. 10.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(31));
  11. 11.🧰 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(4));
  12. 12.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) Welcome, name! (c) Welcome, Arjun! (d) greet
  13. 13.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(1));
  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 50;
    }
    show(fee(9) + fee(4));
  15. 15.🧰 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(12));
  16. 16.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) Hello, name! (b) Hello, Riya! (c) greet (d) Riya
  17. 17.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 3));
  18. 18.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Meera"));     (a) Meera (b) Well done, name! (c) greet (d) Well done, Meera!
  19. 19.🧰 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(11));
  20. 20.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 6));
  21. 21.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(0));
  22. 22.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(19));
  23. 23.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(3));
  24. 24.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(0));
  25. 25.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(37));
  26. 26.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 6));
  27. 27.🧰 What does return do in a function? (a) closes the screen (b) repeats the code (c) deletes the app (d) sends back a value
  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 60;
    }
    show(fee(2) + fee(12));
  29. 29.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun"));     (a) greet (b) Arjun (c) Hello, Arjun! (d) Hello, name!
  30. 30.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 6));
  31. 31.🧰 What is a function? (a) a screen size (b) a named block of code (c) a type of phone (d) a list of colours
  32. 32.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(23));
  33. 33.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 3));
  34. 34.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 2));
  35. 35.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(7));
  36. 36.🧰 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(4) + fee(1));
  37. 37.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(17));
  38. 38.🧰 In function tip(bill), what is bill? (a) a screen (b) a loop (c) a parameter (d) an event
  39. 39.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Meera"));     (a) greet (b) Hi, name! (c) Meera (d) Hi, Meera!
  40. 40.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(0));

Answer key

  1. 30
  2. 39
  3. greet()
  4. to reuse code
  5. 60
  6. Hi, Riya!
  7. Well done, Riya!
  8. 275
  9. 105
  10. 93
  11. 20
  12. Welcome, Arjun!
  13. 50
  14. 50
  15. 60
  16. Hello, Riya!
  17. 30
  18. Well done, Meera!
  19. 20
  20. 120
  21. 40
  22. 57
  23. 50
  24. 60
  25. 111
  26. 150
  27. sends back a value
  28. 60
  29. Hello, Arjun!
  30. 90
  31. a named block of code
  32. 46
  33. 165
  34. 120
  35. 14
  36. 0
  37. 51
  38. a parameter
  39. Hi, Meera!
  40. 50

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