c# Queue values changing inadvertently

-1

The code below changes the value of the first object placed on the queue. This is the code to put the first object on the queue:

//put the initial Ma value on the movingAverageQueue

movingAverageQueue.Enqueue(previousMa)

This line of code changes the first object above I already placed on the queue

previousMa.Close = previousMa.Close - sub/period;

What am I missing in my logic for this code?

here is the full code:

public class MA

{

    public static Queue<DateClose> MAMethod(Queue<DateClose> queue,

        Queue<DateClose> firstMASample, int period)

    {



        Queue<DateClose> sample = new Queue<DateClose>(firstMASample.ToArray());

        Queue<DateClose> movingAverageQueue = new Queue<DateClose>(queue.Count() + 1);

        // get the last item or initial MA value from the queue

        DateClose previousMa = firstMASample.LastOrDefault();

        sample = new Queue<DateClose>(firstMASample.Take(firstMASample.Count - 1));

        DateClose mA = null;

        decimal sub = 0;

        DateClose add = null;

        //put the initial Ma value on the movingAverageQueue

        movingAverageQueue.Enqueue(previousMa);

        foreach (DateClose d in queue.ToList())



        {

            mA = sample.Dequeue();

            sub = mA.Close;

            previousMa.Close = previousMa.Close - sub/period;



            add = d;

            sample.Enqueue(d);

            previousMa.Close = previousMa.Close + add.Close/period;

            previousMa.Date = add.Date;

            movingAverageQueue.Enqueue(previousMa);

            queue.Dequeue();

        }



        return movingAverageQueue;

    }

}

The DateClose class is:

public class DateClose

{

    public DateTime Date { get; set; }

    public decimal Close { get; set; }

}

edited Nov 19 '18 at 21:23

Adam Schiavone

1,20731853

asked Nov 19 '18 at 20:34

Jam66125

596

6

"What am I missing in my logic for this code?" How about you tell us what is happening/not happening? And what you expected to happen/not happen?
– Christopher
Nov 19 '18 at 20:37

1

You assign previousMa in one place. It is assigned to be a reference to the last item in firstMaSample if there is one. You are adding this same reference over and over again to movingAverageQueue. You will end up with a queue where every item in the queue is the same item. Is it possible that you need to discover the difference between value types and reference types? Or have you forgotten to assign previousMa again within the loop?
– Richardissimo
Nov 19 '18 at 21:28

Richardissimo, I realized i should use a deque. I found an amazing one here, github.com/StephenCleary/Deque
– Jam66125
Nov 20 '18 at 13:47

add a comment |

-1

The code below changes the value of the first object placed on the queue. This is the code to put the first object on the queue:

//put the initial Ma value on the movingAverageQueue

movingAverageQueue.Enqueue(previousMa)

This line of code changes the first object above I already placed on the queue

previousMa.Close = previousMa.Close - sub/period;

What am I missing in my logic for this code?

here is the full code:

public class MA

{

    public static Queue<DateClose> MAMethod(Queue<DateClose> queue,

        Queue<DateClose> firstMASample, int period)

    {



        Queue<DateClose> sample = new Queue<DateClose>(firstMASample.ToArray());

        Queue<DateClose> movingAverageQueue = new Queue<DateClose>(queue.Count() + 1);

        // get the last item or initial MA value from the queue

        DateClose previousMa = firstMASample.LastOrDefault();

        sample = new Queue<DateClose>(firstMASample.Take(firstMASample.Count - 1));

        DateClose mA = null;

        decimal sub = 0;

        DateClose add = null;

        //put the initial Ma value on the movingAverageQueue

        movingAverageQueue.Enqueue(previousMa);

        foreach (DateClose d in queue.ToList())



        {

            mA = sample.Dequeue();

            sub = mA.Close;

            previousMa.Close = previousMa.Close - sub/period;



            add = d;

            sample.Enqueue(d);

            previousMa.Close = previousMa.Close + add.Close/period;

            previousMa.Date = add.Date;

            movingAverageQueue.Enqueue(previousMa);

            queue.Dequeue();

        }



        return movingAverageQueue;

    }

}

The DateClose class is:

public class DateClose

{

    public DateTime Date { get; set; }

    public decimal Close { get; set; }

}

edited Nov 19 '18 at 21:23

Adam Schiavone

1,20731853

asked Nov 19 '18 at 20:34

Jam66125

596

6

"What am I missing in my logic for this code?" How about you tell us what is happening/not happening? And what you expected to happen/not happen?
– Christopher
Nov 19 '18 at 20:37

1

You assign previousMa in one place. It is assigned to be a reference to the last item in firstMaSample if there is one. You are adding this same reference over and over again to movingAverageQueue. You will end up with a queue where every item in the queue is the same item. Is it possible that you need to discover the difference between value types and reference types? Or have you forgotten to assign previousMa again within the loop?
– Richardissimo
Nov 19 '18 at 21:28

Richardissimo, I realized i should use a deque. I found an amazing one here, github.com/StephenCleary/Deque
– Jam66125
Nov 20 '18 at 13:47

add a comment |

-1

The code below changes the value of the first object placed on the queue. This is the code to put the first object on the queue:

//put the initial Ma value on the movingAverageQueue

movingAverageQueue.Enqueue(previousMa)

This line of code changes the first object above I already placed on the queue

previousMa.Close = previousMa.Close - sub/period;

What am I missing in my logic for this code?

here is the full code:

public class MA

{

    public static Queue<DateClose> MAMethod(Queue<DateClose> queue,

        Queue<DateClose> firstMASample, int period)

    {



        Queue<DateClose> sample = new Queue<DateClose>(firstMASample.ToArray());

        Queue<DateClose> movingAverageQueue = new Queue<DateClose>(queue.Count() + 1);

        // get the last item or initial MA value from the queue

        DateClose previousMa = firstMASample.LastOrDefault();

        sample = new Queue<DateClose>(firstMASample.Take(firstMASample.Count - 1));

        DateClose mA = null;

        decimal sub = 0;

        DateClose add = null;

        //put the initial Ma value on the movingAverageQueue

        movingAverageQueue.Enqueue(previousMa);

        foreach (DateClose d in queue.ToList())



        {

            mA = sample.Dequeue();

            sub = mA.Close;

            previousMa.Close = previousMa.Close - sub/period;



            add = d;

            sample.Enqueue(d);

            previousMa.Close = previousMa.Close + add.Close/period;

            previousMa.Date = add.Date;

            movingAverageQueue.Enqueue(previousMa);

            queue.Dequeue();

        }



        return movingAverageQueue;

    }

}

The DateClose class is:

public class DateClose

{

    public DateTime Date { get; set; }

    public decimal Close { get; set; }

}

edited Nov 19 '18 at 21:23

Adam Schiavone

1,20731853

asked Nov 19 '18 at 20:34

Jam66125

596

The code below changes the value of the first object placed on the queue. This is the code to put the first object on the queue:

//put the initial Ma value on the movingAverageQueue

movingAverageQueue.Enqueue(previousMa)

This line of code changes the first object above I already placed on the queue

previousMa.Close = previousMa.Close - sub/period;

What am I missing in my logic for this code?

here is the full code:

public class MA

{

    public static Queue<DateClose> MAMethod(Queue<DateClose> queue,

        Queue<DateClose> firstMASample, int period)

    {



        Queue<DateClose> sample = new Queue<DateClose>(firstMASample.ToArray());

        Queue<DateClose> movingAverageQueue = new Queue<DateClose>(queue.Count() + 1);

        // get the last item or initial MA value from the queue

        DateClose previousMa = firstMASample.LastOrDefault();

        sample = new Queue<DateClose>(firstMASample.Take(firstMASample.Count - 1));

        DateClose mA = null;

        decimal sub = 0;

        DateClose add = null;

        //put the initial Ma value on the movingAverageQueue

        movingAverageQueue.Enqueue(previousMa);

        foreach (DateClose d in queue.ToList())



        {

            mA = sample.Dequeue();

            sub = mA.Close;

            previousMa.Close = previousMa.Close - sub/period;



            add = d;

            sample.Enqueue(d);

            previousMa.Close = previousMa.Close + add.Close/period;

            previousMa.Date = add.Date;

            movingAverageQueue.Enqueue(previousMa);

            queue.Dequeue();

        }



        return movingAverageQueue;

    }

}

The DateClose class is:

public class DateClose

{

    public DateTime Date { get; set; }

    public decimal Close { get; set; }

}

c# linq

edited Nov 19 '18 at 21:23

Adam Schiavone

1,20731853

asked Nov 19 '18 at 20:34

Jam66125

596

edited Nov 19 '18 at 21:23

Adam Schiavone

1,20731853

asked Nov 19 '18 at 20:34

Jam66125

596

edited Nov 19 '18 at 21:23

Adam Schiavone

1,20731853

edited Nov 19 '18 at 21:23

Adam Schiavone

1,20731853

edited Nov 19 '18 at 21:23

Adam Schiavone

1,20731853

asked Nov 19 '18 at 20:34

Jam66125

596

asked Nov 19 '18 at 20:34

Jam66125

596

asked Nov 19 '18 at 20:34

Jam66125

596

6

"What am I missing in my logic for this code?" How about you tell us what is happening/not happening? And what you expected to happen/not happen?
– Christopher
Nov 19 '18 at 20:37

1

You assign previousMa in one place. It is assigned to be a reference to the last item in firstMaSample if there is one. You are adding this same reference over and over again to movingAverageQueue. You will end up with a queue where every item in the queue is the same item. Is it possible that you need to discover the difference between value types and reference types? Or have you forgotten to assign previousMa again within the loop?
– Richardissimo
Nov 19 '18 at 21:28

Richardissimo, I realized i should use a deque. I found an amazing one here, github.com/StephenCleary/Deque
– Jam66125
Nov 20 '18 at 13:47

add a comment |

6

"What am I missing in my logic for this code?" How about you tell us what is happening/not happening? And what you expected to happen/not happen?
– Christopher
Nov 19 '18 at 20:37

1

You assign previousMa in one place. It is assigned to be a reference to the last item in firstMaSample if there is one. You are adding this same reference over and over again to movingAverageQueue. You will end up with a queue where every item in the queue is the same item. Is it possible that you need to discover the difference between value types and reference types? Or have you forgotten to assign previousMa again within the loop?
– Richardissimo
Nov 19 '18 at 21:28

Richardissimo, I realized i should use a deque. I found an amazing one here, github.com/StephenCleary/Deque
– Jam66125
Nov 20 '18 at 13:47

"What am I missing in my logic for this code?" How about you tell us what is happening/not happening? And what you expected to happen/not happen?
– Christopher
Nov 19 '18 at 20:37

You assign previousMa in one place. It is assigned to be a reference to the last item in firstMaSample if there is one. You are adding this same reference over and over again to movingAverageQueue. You will end up with a queue where every item in the queue is the same item. Is it possible that you need to discover the difference between value types and reference types? Or have you forgotten to assign previousMa again within the loop?
– Richardissimo
Nov 19 '18 at 21:28

Richardissimo, I realized i should use a deque. I found an amazing one here, github.com/StephenCleary/Deque
– Jam66125
Nov 20 '18 at 13:47

add a comment |

1 Answer
1

active

oldest

votes

In C#, object references are passed by value, and so you are enqueing a reference to that object. The reference in the queue is still pointing to the same memory location, and so when you alter the object you will see those changes when you dequeue that object reference.

Jon Skeet article on C# parameter passing

edited Nov 19 '18 at 21:53

answered Nov 19 '18 at 21:36

William Rigby

86212

object references are passed by value... Perhaps not the best way of phrasing an explanation of "passing by reference" vs "passing by value".
– Richardissimo
Nov 19 '18 at 22:03

I know it sounds a bit strange at first, but that's distinct from pass by reference. The article I linked has a boxed off aside that clarifies this.
– William Rigby
Nov 20 '18 at 1:16

add a comment |

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1 Answer
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1 Answer
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active

oldest

votes

Jon Skeet article on C# parameter passing

edited Nov 19 '18 at 21:53

answered Nov 19 '18 at 21:36

William Rigby

86212

object references are passed by value... Perhaps not the best way of phrasing an explanation of "passing by reference" vs "passing by value".
– Richardissimo
Nov 19 '18 at 22:03

I know it sounds a bit strange at first, but that's distinct from pass by reference. The article I linked has a boxed off aside that clarifies this.
– William Rigby
Nov 20 '18 at 1:16

add a comment |

Jon Skeet article on C# parameter passing

edited Nov 19 '18 at 21:53

answered Nov 19 '18 at 21:36

William Rigby

86212

object references are passed by value... Perhaps not the best way of phrasing an explanation of "passing by reference" vs "passing by value".
– Richardissimo
Nov 19 '18 at 22:03

I know it sounds a bit strange at first, but that's distinct from pass by reference. The article I linked has a boxed off aside that clarifies this.
– William Rigby
Nov 20 '18 at 1:16

add a comment |

Jon Skeet article on C# parameter passing

edited Nov 19 '18 at 21:53

answered Nov 19 '18 at 21:36

William Rigby

86212

Jon Skeet article on C# parameter passing

edited Nov 19 '18 at 21:53

answered Nov 19 '18 at 21:36

William Rigby

86212

edited Nov 19 '18 at 21:53

answered Nov 19 '18 at 21:36

William Rigby

86212

answered Nov 19 '18 at 21:36

William Rigby

86212

answered Nov 19 '18 at 21:36

William Rigby

86212

object references are passed by value... Perhaps not the best way of phrasing an explanation of "passing by reference" vs "passing by value".
– Richardissimo
Nov 19 '18 at 22:03

I know it sounds a bit strange at first, but that's distinct from pass by reference. The article I linked has a boxed off aside that clarifies this.
– William Rigby
Nov 20 '18 at 1:16

add a comment |

object references are passed by value... Perhaps not the best way of phrasing an explanation of "passing by reference" vs "passing by value".
– Richardissimo
Nov 19 '18 at 22:03

I know it sounds a bit strange at first, but that's distinct from pass by reference. The article I linked has a boxed off aside that clarifies this.
– William Rigby
Nov 20 '18 at 1:16

object references are passed by value... Perhaps not the best way of phrasing an explanation of "passing by reference" vs "passing by value".
– Richardissimo
Nov 19 '18 at 22:03

I know it sounds a bit strange at first, but that's distinct from pass by reference. The article I linked has a boxed off aside that clarifies this.
– William Rigby
Nov 20 '18 at 1:16

add a comment |

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