pass-by-value

I just want to check my understanding of C#'s ways of handling things, before I delve too deeply into designing my classes. My current understanding is that: Struct is a value type, meaning it actually contains the data members defined within. Class is a reference type, meaning it contains references to the data members defined within. A method signature passes parameters by value , which means a copy of the value is passed to the inside of the method, making it expensive for large arrays and data structures. A method signature that defines a parameter with the ref or out keywords will instead

This question already has an answer here: Is passing pointer argument, pass by value in C++? 5 answers I don't understand why passing a pointer to a function doesn't change the data being passed in. If the function proto looked like this: void func( int *p ); and func allocated memory to p, why can't it be used outside of the function? I thought that pointers were addresses? Whilst something like this does what you expect: void func(int *p) { *p = 1; } int a = 2; func(&a); // a is now 1 this does not void func(int *p) { p = new int; } int *p = NULL; func(p); // p is still NULL In both cases,

I've recently tried to create a property for a Vector2 field, just to realize that it doesn't work as intended. public Vector2 Position { get; set; } this prevents me from changing the values of its members ( X & Y ) Looking up information on this, I read that creating a property to a Vector2 struct returns only a copy of the original object and not a reference. As a Java developer this confuses me. When are objects in C# passed by value and when are they passed by reference? Are all struct objects passed by value? It is important to realise that everything in C# is passed by value , unless

Possible Duplicate: Is Java pass by reference? public class myClass{ public static void main(String[] args){ myObject obj = new myObject("myName"); changeName(obj); System.out.print(obj.getName()); // This prints "anotherName" } public static void changeName(myObject obj){ obj.setName("anotherName"); } } I know that Java pass by value, but why does it pass obj by reference in previous example and change it? Eng.Fouad Java always passes arguments by value, NOT by reference. In your example, you are still passing obj by its value, not the reference itself. Inside your method changeName , you are

The phrase "pass by reference" is used by C and C++ developers alike but they appear to be used to mean different things. What exactly is the difference between this equivocal phrase in each language? Joseph Mansfield There are questions that already deal with the difference between passing by reference and passing by value . In essence, passing an argument by value to a function means that the function will have its own copy of the argument - its value is copied. Modifying that copy will not modify the original object. However, when passing by reference, the parameter inside the function

I have given a function foo(struct node *n) where n is the head node in a linked list. Now foo should change n s.t. it points to the end of the list. But is this possible with this function signature? Assuming t is the pointer to the end of the list: n = t won't work because the pointer is passed by value. *n = *t won't work because I would overwrite the head of the list. Did I miss something? You would need to use a pointer to a pointer: foo(struct node **n) To change what n points to, you do: *n = t; No, because you have a copy of the value of the pointer that's been passed in. You have no

Possible Duplicate: Is Java “pass-by-reference”? I found an unusual Java method today: private void addShortenedName(ArrayList<String> voiceSetList, String vsName) { if (null == vsName) vsName = ""; else vsName = vsName.trim(); String shortenedVoiceSetName = vsName.substring(0, Math.min(8, vsName.length())); //SCR10638 - Prevent export of empty rows. if (shortenedVoiceSetName.length() > 0) { if (!voiceSetList.contains("#" + shortenedVoiceSetName)) voiceSetList.add("#" + shortenedVoiceSetName); } } According to everything I've read about Java's behavior for passing variables, complex objects or