class Foo
{
public int A 开发者_高级运维{ get; set; }
}
class Program
{
static void Main(string[] args)
{
var f = new Foo();
var ff = f;
Console.WriteLine(f.GetHashCode());
Console.WriteLine(ff.GetHashCode());
FooFoo(ref f);
BarBar(f);
}
private static void BarBar(Foo f)
{
Console.WriteLine(f.GetHashCode());
}
private static void FooFoo(ref Foo f)
{
Console.WriteLine(f.GetHashCode());
}
}
OUTPUT:
58225482
58225482
58225482
58225482
What is the difference between FooFoo
and BarBar
?
No effective difference in this case.
The point of ref
is not to pass a reference to an object, it is to pass a reference to a variable.
Consider the following change:
private static void BarBar(Foo f)
{
Console.WriteLine(f.GetHashCode());
f = new Foo();
}
private static void FooFoo(ref Foo f)
{
Console.WriteLine(f.GetHashCode());
f = new Foo();
}
In this case, the FooFoo
's change will also change the f
variable in the Main
method, but the BarBar
method is only changing a local variable.
All reference types are passed as reference types in any case, you cannot change that. The only point to ref
is to allow the called method to change the variable it is being passed.
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