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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 234 · 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 return do in a function? (a) closes the screen (b) repeats the code (c) sends back a value (d) deletes the app
  2. 2.🧰 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(1) + fee(6));
  3. 3.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman"));     (a) Welcome, Aman! (b) Aman (c) Welcome, name! (d) greet
  4. 4.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 6));
  5. 5.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hello, Zoya! (b) greet (c) Zoya (d) Hello, name!
  6. 6.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 5));
  7. 7.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 2));
  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(11) + fee(7));
  10. 10.🧰 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));
  11. 11.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 5));
  12. 12.🧰 In function tip(bill), what is bill? (a) a screen (b) a parameter (c) an event (d) a loop
  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(3) + fee(10));
  14. 14.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(32));
  15. 15.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(3));
  16. 16.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(45, 6));
  17. 17.🧰 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));
  18. 18.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) Welcome, name! (b) Welcome, Arjun! (c) greet (d) Arjun
  19. 19.🧰 Why write a function? (a) to slow the app (b) to make code longer (c) to hide errors (d) to reuse code
  20. 20.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 4));
  21. 21.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) Well done, Arjun! (b) Well done, name! (c) Arjun (d) greet
  22. 22.🧰 How do you run (call) a function called greet? (a) run greet (b) greet() (c) #greet (d) greet[]
  23. 23.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Zoya (c) Hi, Zoya! (d) Hi, name!
  24. 24.🧰 What is a function? (a) a screen size (b) a list of colours (c) a named block of code (d) a type of phone
  25. 25.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 4));
  26. 26.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir"));     (a) Welcome, Kabir! (b) greet (c) Kabir (d) Welcome, name!
  27. 27.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 5));
  28. 28.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(40, 6));
  29. 29.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(6));
  30. 30.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Zoya"));     (a) Zoya (b) Welcome, name! (c) greet (d) Welcome, Zoya!
  31. 31.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 6));
  32. 32.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 3));
  33. 33.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(50, 2));
  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 30;
    }
    show(fee(4) + fee(6));
  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 60;
    }
    show(fee(4) + fee(1));
  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 30;
    }
    show(fee(12) + fee(6));
  37. 37.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(18));
  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(8) + fee(7));
  39. 39.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Meera"));     (a) Hello, name! (b) greet (c) Meera (d) Hello, Meera!
  40. 40.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(2));

Answer key

  1. sends back a value
  2. 60
  3. Welcome, Aman!
  4. 480
  5. Hello, Zoya!
  6. 75
  7. 70
  8. 50
  9. 60
  10. 30
  11. 400
  12. a parameter
  13. 20
  14. 64
  15. 50
  16. 270
  17. 50
  18. Welcome, Arjun!
  19. to reuse code
  20. 40
  21. Well done, Arjun!
  22. greet()
  23. Hi, Zoya!
  24. a named block of code
  25. 280
  26. Welcome, Kabir!
  27. 50
  28. 240
  29. 12
  30. Welcome, Zoya!
  31. 210
  32. 30
  33. 100
  34. 30
  35. 0
  36. 60
  37. 54
  38. 80
  39. Hello, Meera!
  40. 40

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