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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 898 · 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 points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(2));
  2. 2.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Kabir"));     (a) greet (b) Hi, name! (c) Hi, Kabir! (d) Kabir
  3. 3.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya"));     (a) Riya (b) Hi, Riya! (c) greet (d) Hi, name!
  4. 4.🧰 Why write a function? (a) to slow the app (b) to reuse code (c) to hide errors (d) to make code longer
  5. 5.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(14));
  6. 6.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Meera"));     (a) greet (b) Hello, name! (c) Hello, Meera! (d) Meera
  7. 7.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(3));
  8. 8.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(2));
  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(12) + fee(3));
  10. 10.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(33));
  11. 11.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(35));
  12. 12.🧰 How do you run (call) a function called greet? (a) run greet (b) #greet (c) greet() (d) greet[]
  13. 13.🧰 What is a function? (a) a type of phone (b) a list of colours (c) a named block of code (d) a screen size
  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 60;
    }
    show(fee(7) + fee(6));
  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(8) + fee(9));
  16. 16.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(4));
  17. 17.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Zoya"));     (a) Zoya (b) Well done, Zoya! (c) Well done, name! (d) greet
  18. 18.🧰 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(7));
  19. 19.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir"));     (a) Kabir (b) greet (c) Well done, name! (d) Well done, Kabir!
  20. 20.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(21));
  21. 21.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hello, Zoya! (b) Hello, name! (c) greet (d) Zoya
  22. 22.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(6));
  23. 23.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(18));
  24. 24.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(4));
  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 60;
    }
    show(fee(9) + fee(5));
  26. 26.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 5));
  27. 27.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 5));
  28. 28.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 4));
  29. 29.🧰 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(1) + fee(4));
  30. 30.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(85, 4));
  31. 31.🧰 What does return do in a function? (a) deletes the app (b) closes the screen (c) repeats the code (d) sends back a value
  32. 32.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(20));
  33. 33.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(39));
  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(4) + fee(6));
  35. 35.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Riya"));     (a) Welcome, Riya! (b) Riya (c) Welcome, name! (d) greet
  36. 36.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 4));
  37. 37.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) greet (b) Arjun (c) Welcome, name! (d) Welcome, Arjun!
  38. 38.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(2));
  39. 39.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 6));
  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 50;
    }
    show(fee(4) + fee(7));

Answer key

  1. 60
  2. Hi, Kabir!
  3. Hi, Riya!
  4. to reuse code
  5. 42
  6. Hello, Meera!
  7. 6
  8. 50
  9. 30
  10. 99
  11. 105
  12. greet()
  13. a named block of code
  14. 120
  15. 100
  16. 60
  17. Well done, Zoya!
  18. 50
  19. Well done, Kabir!
  20. 63
  21. Hello, Zoya!
  22. 18
  23. 36
  24. 70
  25. 120
  26. 325
  27. 475
  28. 140
  29. 0
  30. 340
  31. sends back a value
  32. 60
  33. 78
  34. 40
  35. Welcome, Riya!
  36. 260
  37. Welcome, Arjun!
  38. 40
  39. 60
  40. 50

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