MAGIC: modifying a class memeber affects another member, HOW?

[Muhammad Gouda]

Here is the code:

public Document(string title, string source,string summery, string [] filesList, int noOfFiles)
{
this.title = title;
this.source = source;
this.summery = summery;
this.noOfFiles = noOfFiles;
this.filesList = filesList;
this.pathsList = filesList;

		string \[\] temp; 
		
		for(int i=0; i<noOfFiles; i++)
		{
			temp = pathsList\[i\].Split('\\\\');
			this.filesList\[i\] = temp\[temp.Length-1\];
		}
	}

the array pathsList holds the full path of the files the array filesList hold the abstract names of the files As you see in the code, in the loop I update only the filesList The MAGIC is, the pathsList is updated too Can any why tell me how this happens?

Mohammed Gouda foreach(Minute m in MyLife) myExperience++;

[leppie]

Mohammed Gouda wrote:

this.filesList = filesList; this.pathsList = filesList;

Because you are modifying the same instance. Make a copy of pathsList.

xacc.ide - now with TabsToSpaces support
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[DaveyM69]

they both hold a reference to the same string array, so when one alters the array it will be reflected in the other as they are still looking at the same reference. The solution is cloning - which is a whole new rabbit hole!

Dave

[Muhammad Gouda]

Thanks I gussed fixed size array is passed by value not be ref

Mohammed Gouda foreach(Minute m in MyLife) myExperience++;

[PIEBALDconsult]

Yeah, what they said. Personally, I'd do someting more like this:

this.filesList = new string [ filesList.Length ] ;
this.pathsList = new string [ filesList.Length ] ;

System.IO.FileInfo temp ;

for(int i=0; i<noOfFiles; i++)
{
temp = new System.IO.FileInfo ( filesList[i] ) ;

this.pathsList\[i\] = temp.FullName ;
this.filesList\[i\] = temp.Name ;

}

And more likely I'd use List<string>s rather than arrays. I also pass file specifications through System.Environment.ExpandEnvironmentVariables before using them, but that's just me.