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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 306 · 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 does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Zoya (c) Well done, name! (d) Well done, Zoya!
  2. 2.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 6));
  3. 3.🧰 In function tip(bill), what is bill? (a) a loop (b) a screen (c) an event (d) a parameter
  4. 4.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(2));
  5. 5.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(7));
  6. 6.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Kabir"));     (a) Kabir (b) greet (c) Hi, name! (d) Hi, Kabir!
  7. 7.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 4));
  8. 8.🧰 Why write a function? (a) to slow the app (b) to hide errors (c) to reuse code (d) to make code longer
  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 50;
    }
    show(fee(5) + fee(3));
  10. 10.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 2));
  11. 11.🧰 What is a function? (a) a list of colours (b) a screen size (c) a type of phone (d) a named block of code
  12. 12.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(5));
  13. 13.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 3));
  14. 14.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 5));
  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 60;
    }
    show(fee(6) + fee(12));
  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 40;
    }
    show(fee(12) + fee(12));
  17. 17.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(10));
  18. 18.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(2));
  19. 19.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(45, 4));
  20. 20.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(11));
  21. 21.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(19));
  22. 22.🧰 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(2) + fee(11));
  23. 23.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Riya"));     (a) greet (b) Welcome, name! (c) Riya (d) Welcome, Riya!
  24. 24.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir"));     (a) Well done, name! (b) Kabir (c) greet (d) Well done, Kabir!
  25. 25.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 3));
  26. 26.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) Hello, Aman! (b) Hello, name! (c) Aman (d) greet
  27. 27.🧰 What does return do in a function? (a) deletes the app (b) repeats the code (c) closes the screen (d) sends back a value
  28. 28.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) Kabir (b) Hello, Kabir! (c) Hello, name! (d) greet
  29. 29.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(26));
  30. 30.🧰 How do you run (call) a function called greet? (a) greet[] (b) greet() (c) #greet (d) run greet
  31. 31.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(1));
  32. 32.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(40, 4));
  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(3) + fee(10));
  34. 34.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) greet (b) Well done, Riya! (c) Well done, name! (d) Riya
  35. 35.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(6));
  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(9) + fee(7));
  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 30;
    }
    show(fee(7) + fee(2));
  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 20;
    }
    show(fee(9) + fee(5));
  39. 39.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 2));
  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 20;
    }
    show(fee(11) + fee(3));

Answer key

  1. Well done, Zoya!
  2. 120
  3. a parameter
  4. 60
  5. 14
  6. Hi, Kabir!
  7. 140
  8. to reuse code
  9. 50
  10. 70
  11. a named block of code
  12. 100
  13. 240
  14. 75
  15. 120
  16. 80
  17. 20
  18. 40
  19. 180
  20. 33
  21. 57
  22. 30
  23. Welcome, Riya!
  24. Well done, Kabir!
  25. 75
  26. Hello, Aman!
  27. sends back a value
  28. Hello, Kabir!
  29. 52
  30. greet()
  31. 50
  32. 160
  33. 30
  34. Well done, Riya!
  35. 12
  36. 120
  37. 30
  38. 40
  39. 190
  40. 20

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