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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 566 · 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 50;
    }
    show(fee(2) + fee(11));
  2. 2.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Kabir"));     (a) Kabir (b) Hi, name! (c) greet (d) Hi, Kabir!
  3. 3.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Meera"));     (a) Meera (b) Well done, Meera! (c) greet (d) Well done, name!
  4. 4.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) Hello, Riya! (b) greet (c) Riya (d) Hello, name!
  5. 5.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) Hello, Aman! (b) Aman (c) Hello, name! (d) greet
  6. 6.🧰 How do you run (call) a function called greet? (a) greet[] (b) run greet (c) #greet (d) greet()
  7. 7.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(16));
  8. 8.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(24));
  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 30;
    }
    show(fee(2) + fee(9));
  10. 10.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 4));
  11. 11.🧰 Why write a function? (a) to hide errors (b) to reuse code (c) to make code longer (d) to slow the app
  12. 12.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(21));
  13. 13.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Aman (c) Hi, Aman! (d) Hi, name!
  14. 14.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(2));
  15. 15.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Meera"));     (a) Welcome, name! (b) Meera (c) Welcome, Meera! (d) greet
  16. 16.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya"));     (a) Riya (b) greet (c) Hi, name! (d) Hi, Riya!
  17. 17.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(40));
  18. 18.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 2));
  19. 19.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hello, name! (b) greet (c) Hello, Zoya! (d) Zoya
  20. 20.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(1));
  21. 21.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 6));
  22. 22.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(17));
  23. 23.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(90, 3));
  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 50;
    }
    show(fee(4) + fee(11));
  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 20;
    }
    show(fee(6) + fee(8));
  26. 26.🧰 What is a function? (a) a list of colours (b) a named block of code (c) a screen size (d) a type of phone
  27. 27.🧰 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(10) + fee(4));
  28. 28.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(21));
  29. 29.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir"));     (a) Kabir (b) Welcome, Kabir! (c) Welcome, name! (d) greet
  30. 30.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(31));
  31. 31.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) greet (c) Well done, name! (d) Well done, Arjun!
  32. 32.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(0));
  33. 33.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(38));
  34. 34.🧰 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(10) + fee(3));
  35. 35.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) Welcome, Arjun! (b) Arjun (c) Welcome, name! (d) greet
  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 20;
    }
    show(fee(5) + fee(4));
  37. 37.🧰 What does return do in a function? (a) closes the screen (b) sends back a value (c) repeats the code (d) deletes the app
  38. 38.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(8));
  39. 39.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(4));
  40. 40.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 6));

Answer key

  1. 50
  2. Hi, Kabir!
  3. Well done, Meera!
  4. Hello, Riya!
  5. Hello, Aman!
  6. greet()
  7. 48
  8. 72
  9. 30
  10. 100
  11. to reuse code
  12. 42
  13. Hi, Aman!
  14. 50
  15. Welcome, Meera!
  16. Hi, Riya!
  17. 80
  18. 200
  19. Hello, Zoya!
  20. 30
  21. 210
  22. 34
  23. 270
  24. 50
  25. 40
  26. a named block of code
  27. 40
  28. 63
  29. Welcome, Kabir!
  30. 93
  31. Well done, Arjun!
  32. 30
  33. 76
  34. 40
  35. Welcome, Arjun!
  36. 20
  37. sends back a value
  38. 24
  39. 70
  40. 150

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