CODEWITHSUNDEEP
c#pointersunsafememory-addressread-write
nawfal
nawfal

Reputation: 73193

How to write to memory address?

New to pointers and unsafe world in C#. I was going through getting memory address of variables via pointers, move things around a bit here and there etc; basically learning. 

static unsafe void M()
{
    var i = 1;
    var p = &i; //gets memory location of variable i here

    //how do I write to location p, say a value of 100?
}

I was wondering if there is a way to write to a specific location as well? It helps a great deal to see what's going around if I can read and write at the same time.

No practical purposes, just learning. Or is it not possible with C#?

Upvotes: 2

Views: 3026

Answers (3)

Moo-Juice
Moo-Juice

Reputation: 38800

You need to deference it.

Here's a LINQPad snippet:

int i = 1;

unsafe
{
    var p = &i;

    *p = 100;
}

i.Dump();

This outputs "100", as expected.

Upvotes: 1

Brian Rasmussen
Brian Rasmussen

Reputation: 116411

Like this

*p = 100;

Console.WriteLine(i); // prints 100;

Upvotes: 1

user427390
user427390

Reputation:

You need to dereference the pointer with the * operator. ex: 

*p = 100;

Upvotes: 1

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