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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 731 · 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(9) + fee(2));
  2. 2.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun"));     (a) greet (b) Hello, Arjun! (c) Arjun (d) Hello, name!
  3. 3.🧰 How do you run (call) a function called greet? (a) greet() (b) greet[] (c) run greet (d) #greet
  4. 4.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 3));
  5. 5.🧰 What is a function? (a) a list of colours (b) a type of phone (c) a named block of code (d) a screen size
  6. 6.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hello, Zoya! (b) Hello, name! (c) greet (d) Zoya
  7. 7.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(39));
  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 50;
    }
    show(fee(10) + fee(9));
  9. 9.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(2));
  10. 10.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(5));
  11. 11.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(45, 4));
  12. 12.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(11));
  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 20;
    }
    show(fee(12) + fee(1));
  14. 14.🧰 Why write a function? (a) to slow the app (b) to hide errors (c) to reuse code (d) to make code longer
  15. 15.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(40, 4));
  16. 16.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(1));
  17. 17.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 5));
  18. 18.🧰 In function tip(bill), what is bill? (a) a parameter (b) a loop (c) a screen (d) an event
  19. 19.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) Hello, Aman! (b) Hello, name! (c) Aman (d) greet
  20. 20.🧰 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(10));
  21. 21.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya"));     (a) Hi, name! (b) Riya (c) greet (d) Hi, Riya!
  22. 22.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(3));
  23. 23.🧰 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(11));
  24. 24.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(13));
  25. 25.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Kabir"));     (a) Kabir (b) Hi, Kabir! (c) greet (d) Hi, name!
  26. 26.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 6));
  27. 27.🧰 What does return do in a function? (a) closes the screen (b) sends back a value (c) deletes the app (d) repeats the code
  28. 28.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(3));
  29. 29.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(16));
  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(8) + fee(2));
  31. 31.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(1));
  32. 32.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) Well done, name! (c) greet (d) Well done, Arjun!
  33. 33.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(11));
  34. 34.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 4));
  35. 35.🧰 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(10));
  36. 36.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 3));
  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(3) + fee(8));
  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 60;
    }
    show(fee(5) + fee(6));
  39. 39.🧰 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(5));
  40. 40.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) Zoya (b) Hi, name! (c) greet (d) Hi, Zoya!

Answer key

  1. 50
  2. Hello, Arjun!
  3. greet()
  4. 300
  5. a named block of code
  6. Hello, Zoya!
  7. 78
  8. 100
  9. 80
  10. 15
  11. 180
  12. 33
  13. 20
  14. to reuse code
  15. 160
  16. 70
  17. 300
  18. a parameter
  19. Hello, Aman!
  20. 120
  21. Hi, Riya!
  22. 80
  23. 100
  24. 39
  25. Hi, Kabir!
  26. 60
  27. sends back a value
  28. 9
  29. 32
  30. 20
  31. 30
  32. Well done, Arjun!
  33. 22
  34. 400
  35. 50
  36. 195
  37. 30
  38. 120
  39. 40
  40. Hi, Zoya!

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