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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 432 · 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 "Hi, " + name + "!";
    }
    show(greet("Riya"));     (a) Hi, name! (b) Hi, Riya! (c) Riya (d) greet
  2. 2.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 5));
  3. 3.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(19));
  4. 4.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(3));
  5. 5.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(21));
  6. 6.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(31));
  7. 7.🧰 What does return do in a function? (a) closes the screen (b) sends back a value (c) deletes the app (d) repeats the code
  8. 8.🧰 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(4));
  9. 9.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(1));
  10. 10.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 2));
  11. 11.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 2));
  12. 12.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 6));
  13. 13.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 5));
  14. 14.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hello, Kabir! (b) Hello, name! (c) greet (d) Kabir
  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(4) + fee(3));
  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(10) + fee(3));
  17. 17.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(13));
  18. 18.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir"));     (a) Kabir (b) Welcome, name! (c) greet (d) Welcome, Kabir!
  19. 19.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(37));
  20. 20.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 5));
  21. 21.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman"));     (a) Hi, name! (b) greet (c) Hi, Aman! (d) Aman
  22. 22.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(36));
  23. 23.🧰 What is a function? (a) a screen size (b) a list of colours (c) a type of phone (d) a named block of code
  24. 24.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Meera"));     (a) Hello, name! (b) greet (c) Hello, Meera! (d) Meera
  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(6) + fee(9));
  26. 26.🧰 Why write a function? (a) to reuse code (b) to make code longer (c) to hide errors (d) to slow the app
  27. 27.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 2));
  28. 28.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Aman (c) Hello, name! (d) Hello, Aman!
  29. 29.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Hi, name! (c) Zoya (d) Hi, Zoya!
  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 20;
    }
    show(fee(10) + fee(2));
  31. 31.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(10));
  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 40;
    }
    show(fee(9) + fee(9));
  33. 33.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 4));
  34. 34.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 3));
  35. 35.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(28));
  36. 36.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 3));
  37. 37.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 4));
  38. 38.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Well done, name! (b) greet (c) Well done, Riya! (d) Riya
  39. 39.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Aman (c) Welcome, Aman! (d) Welcome, name!
  40. 40.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(85, 4));

Answer key

  1. Hi, Riya!
  2. 275
  3. 57
  4. 60
  5. 63
  6. 93
  7. sends back a value
  8. 20
  9. 30
  10. 130
  11. 70
  12. 150
  13. 400
  14. Hello, Kabir!
  15. 0
  16. 60
  17. 39
  18. Welcome, Kabir!
  19. 111
  20. 100
  21. Hi, Aman!
  22. 72
  23. a named block of code
  24. Hello, Meera!
  25. 60
  26. to reuse code
  27. 140
  28. Hello, Aman!
  29. Hi, Zoya!
  30. 20
  31. 30
  32. 80
  33. 140
  34. 30
  35. 84
  36. 210
  37. 80
  38. Well done, Riya!
  39. Welcome, Aman!
  40. 340

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