Difference between Class variable, Member variable, and Local variable, Global Variable [closed]

Answer 1

Going a little further than the linked question in the comments about "local" variables...

A "local" variable is a variable which the lifetime is defined by the curly brackets in which it is contained. For example:

void SomeMethod()
{
    int a = 0;    //a is a local variable that is alive from this point down to }
}

But there are other types of local variables, for example:

void SomeMethod()
{
    for (int i = 0; i < 10; i++)
    {
        int a = 0;
        //a and i are local inside this for loop
    }
    //i and a do not exist here
}

Or even something like this is valid (but not recommended):

void SomeMethod()
{
    int x = 0;
    {
         int a = 0;
         //a exists inside here, until the next }
         //x also exists in here because its defined in a parent scope
    }
    //a does not exist here, but x does
}

The { and } are scoping delimiters. They define a scope of something. When defined under a method, they define the scope for the code that belongs to the method. They also define the scope of things like for, if, switch, class, etc. They define a local scope.

For completeness, here is a class/member variable:

public class SomeClass
{
    public int SomeVariable;
}

Here, SomeVariable is defined in the SomeClass scope, and can be accessed through instances of the SomeClass class:

SomeClass sc = new SomeClass();
sc.SomeVariable = 10;

People call static variables class variables but I don't agree with the definition, static classes are like singleton instances and I like to think of them as member variables.

Its also highly recommended that you use properties instead of public mutable members when exposing data outside a class.