NP54 Declaring different way

19y2.5kVisual Basic .NET

Hi Guys

I wish to know is there any difference in declaring a variable in different way for example:

int x;

Same variable is declared in different way

int x = new int();

The article in the following website give rise to this question. Anyone knows please explain.

http://www.c-sharpcorner.com/UploadFile/rmcochran/csharp_memory01122006130034PM/csharp_memory.aspx

Thank you

This implimention is in the article

public int ReturnValue()
{
         int x = new int();
         x = 3;
         int y = new int();
         y = x;
         y = 4;
         return x;
}

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

19y ago
Thank you very much for the explanation, Alan
Alan19y ago
Although the 'int' type (or System.Int32 to give it its full title) has a default parameterless constructor, it is seldom used because all it does is create a new int with the value of zero.

So, these lines do exactly the same thing:

int x = 0;

int x = new int();

However, this line (within a method or property) is different:

int x;

What that does is create a new local 'int' variable called 'x' but no value is assigned to it. The compiler therefore regards it as unassigned until you do assign a value to it. Consequently, the compiler produces an error if you try (or you appear to be trying) to use that variable without giving it a value first.

On the other hand if the same line is used as the declaration of a field, rather than a local variable, the compiler will allow it because (by default) all int fields are given a value of zero.