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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 709 · 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 number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 5));
  2. 2.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) greet (b) Hello, name! (c) Riya (d) Hello, Riya!
  3. 3.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 4));
  4. 4.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hi, name! (b) Hi, Kabir! (c) Kabir (d) greet
  5. 5.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(28));
  6. 6.🧰 Why write a function? (a) to slow the app (b) to make code longer (c) to reuse code (d) to hide errors
  7. 7.🧰 In function tip(bill), what is bill? (a) a loop (b) a screen (c) an event (d) a parameter
  8. 8.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(17));
  9. 9.🧰 What does return do in a function? (a) repeats the code (b) deletes the app (c) closes the screen (d) sends back a value
  10. 10.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(26));
  11. 11.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 3));
  12. 12.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(75, 2));
  13. 13.🧰 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(3) + fee(10));
  14. 14.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(0));
  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 50;
    }
    show(fee(9) + fee(8));
  16. 16.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(30));
  17. 17.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(85, 2));
  18. 18.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 2));
  19. 19.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(3));
  20. 20.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(37));
  21. 21.🧰 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));
  22. 22.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 2));
  23. 23.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Meera"));     (a) greet (b) Meera (c) Well done, Meera! (d) Well done, name!
  24. 24.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman"));     (a) Aman (b) Welcome, name! (c) Welcome, Aman! (d) greet
  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 30;
    }
    show(fee(2) + fee(11));
  26. 26.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(1));
  27. 27.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(4));
  28. 28.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(90, 5));
  29. 29.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(5));
  30. 30.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 5));
  31. 31.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Meera"));     (a) Hi, name! (b) Hi, Meera! (c) greet (d) Meera
  32. 32.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(19));
  33. 33.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(37));
  34. 34.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(3));
  35. 35.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(35));
  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(5) + fee(8));
  37. 37.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(1));
  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 40;
    }
    show(fee(3) + fee(1));
  39. 39.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hello, name! (b) Kabir (c) greet (d) Hello, Kabir!
  40. 40.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) Hello, Arjun! (c) greet (d) Hello, name!

Answer key

  1. 150
  2. Hello, Riya!
  3. 400
  4. Hi, Kabir!
  5. 56
  6. to reuse code
  7. a parameter
  8. 51
  9. sends back a value
  10. 52
  11. 285
  12. 150
  13. 60
  14. 60
  15. 100
  16. 60
  17. 170
  18. 190
  19. 50
  20. 111
  21. 60
  22. 20
  23. Well done, Meera!
  24. Welcome, Aman!
  25. 30
  26. 70
  27. 12
  28. 450
  29. 15
  30. 125
  31. Hi, Meera!
  32. 38
  33. 74
  34. 90
  35. 105
  36. 120
  37. 50
  38. 0
  39. Hello, Kabir!
  40. Hello, Arjun!

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