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How to use properties with an integral overflow (byte)?

I am fairly new to programming and C#, and I am creating a game using C# 9.0 in which all instances of Entity have certain stats. I want to be able to change their private data fields using properties, though I'm not entirely sure how properties work. I know they are useful in encapsulation as getters and setters.
Context:
I am trying to optimize code and decrease memory usage where possible
The byte field str should be variable (through events, training, etc.), but have a "ceiling" and "floor"
If dog.str = 253, then dog.Str += 5; should result in dog.str being 255
If dog.str = 2, then dog.Str -= 5; should result in dog.str being 0
private byte str;
public short Str
{
get => str;
set
{
if (value > byte.MaxValue) str = byte.MaxValue; //Pos Overflow
else if (value < byte.MinValue) str = byte.MinValue; //Neg Overflow
else str = (byte)value;
}
}
Questions:
Since the property is of datatype Short, does it create a new private backing field that consumes memory? Or is value/Str{set;} just a local variable that later disappears?
Does the property public float StrMod {get => (float)(str*Effects.Power);} create a backing field? Would it be better to just create a method like public float getStrMod() instead?
Is this code optimal for what I'm trying to achieve? Is there some better way to do this, considering the following?
If for some reason the Short overflowed (unlikely in this scenario, but there may be a similar situation), then I would end up with the same problem. However, if extra memory allocation isn't an issue, then I could use an int.
The {get;} will return a Short, which may or may not be an issue.

Question 1:
No it doesn't, its backing field is str.
Question 2:
Profile your code first instead of making random changes in hope to reduce memory usage.
"Premature optimization is the root of all evil", do you really have such issues at this point ?
Personally I'd use int and use same type for property and backing field for simplicity.
This would avoid wrapping such as assigning 32768 which would then result as -32768 for short.
Side note, don't think that using byte necessarily results in 1 byte, if you have tight packing requirements then you need to look at StructLayoutAttribute.Pack.
Other than that I see nothing wrong with your code, just get it to work first then optimize it!
Here's how I'd write your code, maybe you'll get some ideas from it:
class Testing
{
private int _value;
public int Value
{
get => _value;
set => _value = Clamp(value, byte.MinValue, byte.MaxValue);
}
private static int Clamp(int value, int min, int max)
{
return Math.Max(min, Math.Min(max, value));
}
}
EDIT:
Different scenarios:
class Testing
{
private int _value1;
public int Value1 // backing field is _value1
{
get => _value1;
set => _value1 = value;
}
public int Value2 { get; set; } // adds a backing field
public int Value3 { get; } // adds a backing field
public int Value4 => 42; // no backing field
}
As you might have guessed, properties are syntactic sugar for methods, they can do 'whatever' under the hood compared to a field which can only be assigned a value to.
Also, one difference with a method is that you can browse its value in the debugger, that's handy.
Suggested reading:
https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/classes-and-structs/properties
Finally, properties are expected to return quickly, else write a method, and possibly async if it's going to take a while (advantage to method in this case as properties can't be async).

#aybe answer covers main thing about you question. I would like to add additional info to your 2nd question. You should consider on which platform you write application. There is a word term:
In computing, a word is the natural unit of data used by a particular
processor design. A word is a fixed-sized piece of data handled as a
unit by the instruction set or the hardware of the processor. The
number of bits in a word (the word size, word width, or word length)
is an important characteristic of any specific processor design or
computer architecture.
If processor has 64 bit word, then every variable which type is less than 64 bits will still occupy 64 bits in memory. Keep in mind that variable of given type will be handled as given type and size in memory doesn't impact range, overflow or underflow - arithmetic will be processed for given type.
In short - if you have 64-bit desktop processor and you will use only short variables, then you will not observe any memory savings in comparison to declaring int variables.

Stackoverflow only with very large ArrayLists

I'm using a recursive version of the insertion sort algorithm to sort 5000 objects based upon a randomly generated integer property, but I've been getting a stackoverflow exception only at an ArrayList of this size while working fine for ArrayLists of other sizes.
I used Console.WriteLine to see what the "position" integer goes up to in one of my methods and it ends up at `4719 before skipping a line and giving a stackoverflow exception. How should I get around this?
I should also mention that when testing an iterative version of insertion sort in the same Visual Studio solution and using an ArrayList of the same size of objects I do not get a stackoverflow exception.
My code for the recursive insertion sort is below (AL is the ArrayList):
public void IS()
{
ISRM(0);
}
private void ISRM(int position)
{
if (position == AL.Count)
return;
Console.WriteLine(position);
int PositionNext = position + 1;
ISRMNext(position, PositionNext);
ISRM(position + 1);
}
private void ISRMNext(int position, int PositionNext)
{
if ((PositionNext == 0) || (PositionNext == AL.Count))
return;
Webpage EntryNext = (Webpage)AL[PositionNext];
Webpage EntryBefore = (Webpage)AL[PositionNext - 1];
if (EntryBefore.getVisitCount() < EntryNext.getVisitCount())
{
Webpage temp = EntryBefore;
AL[PositionNext - 1] = AL[PositionNext];
AL[PositionNext] = temp;
}
ISRMNext(position, PositionNext - 1);
}

Well, first of all, sorting through recursive call is a bad idea for several reasons.
As you've already found out, this easily leads to a stack overflow due to limited size of the stack.
It will have poor performance by definition since function call and accompanying allocation of local function context on the stack is much more expensive operation compared to something like while or for operators iterating through plain collection.
These are two reasons why #Zer0 probably suggested it, but there's more to it.
There's ready ArrayList.Sort() method waiting for you that takes custom comparator. All you need is to write said comparator for your custom objects according to whatever rules you want and call Sort(your_comparator). That's it. You do not need to re-invent the wheel implementing your own sorting method itself - unless implementing sorting method is the actual goal of your program... but I honestly doubt it.
So, It could be something like this (not tested!):
class MyComparer : IComparer
{
public int Compare(object x, object y)
{
var _x = ((Webpage) x).getVisitCount();
var _y = ((Webpage) y).getVisitCount();
if (_x < _y)
{
return -1;
}
if (_x > _y)
{
return 1;
}
return 0;
}
}
Usage:
var myAL = new ArrayList();
// ... filling up the myAL
myAL.Sort(new MyComparer());

Struct variables not changing

I feel like I'm missing something complete obvious so I apologise in advance if (when?) that is the case.
I'm trying to do something really simple, change a bool value in a struct from false to true. Obviously I can't change it directly, so I created a method within the struct that I can call which should change the value there. It doesn't seem to be the case. Here is the code and I'd appreciate any insight;
public Dictionary<int, List<ScanLineNode>> allScanLineNodes = new Dictionary<int, List<ScanLineNode>>();
public void MethodName(ScanLineNode node [...])
{
//This will perform a raycast from the Node's position in the specified direction. If the raycast hits nothing, it will return Vector3.zero ('Row is complete'), otherwise will return the hit point
Vector3 terminationPoint = node.RaycastDirection(node, direction, maxDist, targetRaycast, replacementColour, backgroundColour);
ScanLineNode terminationNode = new ScanLineNode();
//Previously attempted to store a local reference to this row being used, but also did not work
//List<ScanLineNode> rowNodes = allScanLineNodes[node.rowNumber];
[...]
if (terminationPoint == Vector3.zero)
{
//Definitely reaches this point, and executes this function along the row, I have added breakpoints and checked what happens in this for loop. After running 'RowComplete' (which just changes 'rowComplete' from false to true) 'rowComplete' is still false. Just in case I've included the RowComplete() function below.
Debug.Log("Row Complete: " + node.rowNumber);
for (int i = 0; i < allScanLineNodes[node.rowNumber].Count; i++)
{
allScanLineNodes[node.rowNumber][i].RowCompleted();
}
}
}
ScanLineNode Struct -- Most stuff is hidden (that I don't believe is affecting this), I have included the RowComplete() function however.
public struct ScanLineNode
{
[...]
public bool rowComplete;
[...]
public ScanLineNode([...])
{
[...]
rowComplete = false;
[...]
}
public void RowCompleted()
{
rowComplete = true;
}
}
I have also confirmed that RowCOmpleted() does not get called anywhere aside the above location, and 'rowComplete' is only called from the RowComplete() function

(from comments) allScanLineNodes is a Dictionary<int, List<ScanLineNode>>
Right; the indexer for a List<ScanLineNode> returns a copy of the struct. So when you call the method - you are calling it on a disconnected value on the stack that evaporates a moment later (is overwritten on the stack - this isn't the garbage collector).
This is a common error with mutable structs. Your best bet is probably: don't make mutable structs. But... you could copy it out, mutate it, and then push the mutated value back in:
var list = allScanLineNodes[node.rowNumber];
var val = list[i];
val.RowCompleted();
list[i] = val; // push value back in
But immutable is usually more reliable.
Note: you can get away with this with arrays, since the indexer from an array provides access to a reference to the in-place struct - rather than a copy of the value. But: this isn't a recommendation, as relying on this subtle difference can cause confusion and bugs.

A couple of questions about optimising code for speed in C#

If I have a method that is called many times, such as:
public int CalledManyTimes(int a, int b)
{
MyObject myObject = new myObject();
int c = a + b + myObject.GetSomeValue();
return c;
}
Is there a performance boost by putting MyObject myObject; outside of the method, so it's only declared once, or will the compiler do this automatically?
How exactly are structs passed around?
I'm passing in a Point struct to a method (Point contains only int x, int y), and that method is altering the value and returning a new Point(newX, newY); Is it better to alter the Point that was passed into the method and return that? Or can I create a Point point; outside the method as proposed in my first question and use that?

myObject appears to have no useful state; so: make that a static method - problem solved; no allocation, no virtual call:
public int CalledManyTimes(int a, int b)
{
int c = a + b + MyObject.GetSomeValue(); // static method
return c;
}
For anything else: profile.
Looking at your specific questions:
Is there a performance boost by putting MyObject myObject; outside of the method, so it's only declared once, or will the compiler do this automatically?
Initializing it zero times is even faster. However, if there is some state that isn't obvious in the question, then yes, I would expect it to be more efficient to reuse a single instance - however, that changes the semantic (in the original the state is not shared between iterations).
How exactly are structs passed around?
By default, they are copied on the stack as soon as you so much as glance in their direction. You can use ref to avoid the copy, which may be useful if the struct is massively overweight, or need to be updated (ideally with reassignment, rather than mutability).

Can parameters be constant?

I'm looking for the C# equivalent of Java's final. Does it exist?
Does C# have anything like the following:
public Foo(final int bar);
In the above example, bar is a read only variable and cannot be changed by Foo(). Is there any way to do this in C#?
For instance, maybe I have a long method that will be working with x, y, and z coordinates of some object (ints). I want to be absolutely certain that the function doesn't alter these values in any way, thereby corrupting the data. Thus, I would like to declare them readonly.
public Foo(int x, int y, int z) {
// do stuff
x++; // oops. This corrupts the data. Can this be caught at compile time?
// do more stuff, assuming x is still the original value.
}

Unfortunately you cannot do this in C#.
The const keyword can only be used for local variables and fields.
The readonly keyword can only be used on fields.
NOTE: The Java language also supports having final parameters to a method. This functionality is non-existent in C#.
from http://www.25hoursaday.com/CsharpVsJava.html
EDIT (2019/08/13):
I'm throwing this in for visibility since this is accepted and highest on the list. It's now kind of possible with in parameters. See the answer below this one for details.

This is now possible in C# version 7.2:
You can use the in keyword in the method signature. MSDN documentation.
The in keyword should be added before specifying a method's argument.
Example, a valid method in C# 7.2:
public long Add(in long x, in long y)
{
return x + y;
}
While the following is not allowed:
public long Add(in long x, in long y)
{
x = 10; // It is not allowed to modify an in-argument.
return x + y;
}
Following error will be shown when trying to modify either x or y since they are marked with in:
Cannot assign to variable 'in long' because it is a readonly variable
Marking an argument with in means:
This method does not modify the value of the argument used as this parameter.

The answer: C# doesn't have the const functionality like C++.
I agree with Bennett Dill.
The const keyword is very useful. In the example, you used an int and people don't get your point. But, why if you parameter is an user huge and complex object that can't be changed inside that function? That's the use of const keyword: parameter can't change inside that method because [whatever reason here] that doesn't matters for that method. Const keyword is very powerful and I really miss it in C#.

Here's a short and sweet answer that will probably get a lot of down votes. I haven't read all of the posts and comments, so please forgive me if this has been previously suggested.
Why not take your parameters and pass them into an object that exposes them as immutable and then use that object in your method?
I realize this is probably a very obvious work around that has already been considered and the OP is trying to avoid doing this by asking this question, but I felt it should be here none-the-less...
Good luck :-)

I'll start with the int portion. int is a value type, and in .Net that means you really are dealing with a copy. It's a really weird design constraint to tell a method "You can have a copy of this value. It's your copy, not mine; I'll never see it again. But you can't change the copy." It's implicit in the method call that copying this value is okay, otherwise we couldn't have safely called the method. If the method needs the original, leave it to the implementer to make a copy to save it. Either give the method the value or do not give the method the value. Don't go all wishy-washy in between.
Let's move on to reference types. Now it gets a little confusing. Do you mean a constant reference, where the reference itself cannot be changed, or a completely locked, unchangeable object? If the former, references in .Net by default are passed by value. That is, you get a copy of the reference. So we have essentially the same situation as for value types. If the implementor will need the original reference they can keep it themselves.
That just leaves us with constant (locked/immutable) object. This might seem okay from a runtime perspective, but how is the compiler to enforce it? Since properties and methods can all have side effects, you'd essentially be limited to read-only field access. Such an object isn't likely to be very interesting.

Create an interface for your class that has only readonly property accessors. Then have your parameter be of that interface rather than the class itself. Example:
public interface IExample
{
int ReadonlyValue { get; }
}
public class Example : IExample
{
public int Value { get; set; }
public int ReadonlyValue { get { return this.Value; } }
}
public void Foo(IExample example)
{
// Now only has access to the get accessors for the properties
}
For structs, create a generic const wrapper.
public struct Const<T>
{
public T Value { get; private set; }
public Const(T value)
{
this.Value = value;
}
}
public Foo(Const<float> X, Const<float> Y, Const<float> Z)
{
// Can only read these values
}
Its worth noting though, that its strange that you want to do what you're asking to do regarding structs, as the writer of the method you should expect to know whats going on in that method. It won't affect the values passed in to modify them within the method, so your only concern is making sure you behave yourself in the method you're writing. There comes a point where vigilance and clean code are the key, over enforcing const and other such rules.

I know this might be little late.
But for people that are still searching other ways for this, there might be another way around this limitation of C# standard.
We could write wrapper class ReadOnly<T> where T : struct.
With implicit conversion to base type T.
But only explicit conversion to wrapper<T> class.
Which will enforce compiler errors if developer tries implicit set to value of ReadOnly<T> type.
As I will demonstrate two possible uses below.
USAGE 1 required caller definition to change. This usage will have only use in testing for correctness of your "TestCalled" functions code. While on release level/builds you shouldn't use it. Since in large scale mathematical operations might overkill in conversions, and make your code slow. I wouldn't use it, but for demonstration purpose only I have posted it.
USAGE 2 which I would suggest, has Debug vs Release use demonstrated in TestCalled2 function. Also there would be no conversion in TestCaller function when using this approach, but it requires a little more of coding of TestCaller2 definitions using compiler conditioning. You can notice compiler errors in debug configuration, while on release configuration all code in TestCalled2 function will compile successfully.
using System;
using System.Collections.Generic;
public class ReadOnly<VT>
where VT : struct
{
private VT value;
public ReadOnly(VT value)
{
this.value = value;
}
public static implicit operator VT(ReadOnly<VT> rvalue)
{
return rvalue.value;
}
public static explicit operator ReadOnly<VT>(VT rvalue)
{
return new ReadOnly<VT>(rvalue);
}
}
public static class TestFunctionArguments
{
static void TestCall()
{
long a = 0;
// CALL USAGE 1.
// explicite cast must exist in call to this function
// and clearly states it will be readonly inside TestCalled function.
TestCalled(a); // invalid call, we must explicit cast to ReadOnly<T>
TestCalled((ReadOnly<long>)a); // explicit cast to ReadOnly<T>
// CALL USAGE 2.
// Debug vs Release call has no difference - no compiler errors
TestCalled2(a);
}
// ARG USAGE 1.
static void TestCalled(ReadOnly<long> a)
{
// invalid operations, compiler errors
a = 10L;
a += 2L;
a -= 2L;
a *= 2L;
a /= 2L;
a++;
a--;
// valid operations
long l;
l = a + 2;
l = a - 2;
l = a * 2;
l = a / 2;
l = a ^ 2;
l = a | 2;
l = a & 2;
l = a << 2;
l = a >> 2;
l = ~a;
}
// ARG USAGE 2.
#if DEBUG
static void TestCalled2(long a2_writable)
{
ReadOnly<long> a = new ReadOnly<long>(a2_writable);
#else
static void TestCalled2(long a)
{
#endif
// invalid operations
// compiler will have errors in debug configuration
// compiler will compile in release
a = 10L;
a += 2L;
a -= 2L;
a *= 2L;
a /= 2L;
a++;
a--;
// valid operations
// compiler will compile in both, debug and release configurations
long l;
l = a + 2;
l = a - 2;
l = a * 2;
l = a / 2;
l = a ^ 2;
l = a | 2;
l = a & 2;
l = a << 2;
l = a >> 2;
l = ~a;
}
}

If you often run into trouble like this then you should consider "apps hungarian". The good kind, as opposed to the bad kind. While this doesn't normally tries to express constant-ness of a method parameter (that's just too unusual), there is certainly nothing that stops you from tacking an extra "c" before the identifier name.
To all those aching to slam the downvote button now, please read the opinions of these luminaries on the topic:
Eric Lippert
Larry Osterman
Joel Spolsky

If struct is passed into a method, unless it's passed by ref, it will not be changed by the method it's passed into. So in that sense, yes.
Can you create a parameter whose value can't be assigned within the method or whose properties cannot be set while within the method? No. You cannot prevent the value from being assigned within the method, but you can prevent it's properties from being set by creating an immutable type.
The question isn't whether the parameter or it's properties can be assigned to within the method. The question is what it will be when the method exits.
The only time any outside data is going to be altered is if you pass a class in and change one of it's properties, or if you pass a value by using the ref keyword. The situation you've outlined does neither.

The recommended (well, by me) is to use an interface that provides read only access to the members. Remembering that if the "real" member is a reference type, then only provide access to an interface supporting read operations for that type -- recursing down the entire object hierarchy.