Ref and out Para

mukesh bharagava

8y835Learn iOS Programming

difference between ref and out parameter in c#

5 Replies

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

Vincent Maverick Durano8y ago
Googling your question should give tons of results explaining the difference between them.
Jignesh Kumar8y ago
Please find below link for the same where some improvement done in C# 7.0

https://www.c-sharpcorner.com/article/new-c-sharp-7-features-ref-returns-and-out-variables-part-three/
Sanwar Ranwa8y ago
Hello Mukesh Bharagava

Ref and out parameters are used to pass an argument within a method. In this article, you will learn the differences between these two parameters.

Ref

The ref keyword is used to pass an argument as a reference. This means that when value of that parameter is changed in the method, it gets reflected in the calling method. An argument that is passed using a ref keyword must be initialized in the calling method before it is passed to the called method.

Out

The out keyword is also used to pass an argument like ref keyword, but the argument can be passed without assigning any value to it. An argument that is passed using an out keyword must be initialized in the called method before it returns back to calling method.

Please Check these links for more details

https://www.c-sharpcorner.com/UploadFile/ff2f08/ref-vs-out-keywords-in-C-Sharp/

https://www.dotnettricks.com/learn/csharp/difference-between-ref-and-out-parameters

https://www.aspdotnet-suresh.com/2014/06/csharp-difference-between-ref-and-out-parameters-example.html
Jaish Mathews8y ago
You got Ref. to check and if still not clear, its just the matter of where to initialize ref & out variables. Ref variables to initialize inside calling method itself and out variable to be initialized inisde called method. Any break of these rules would produce compile time error.

Please try with below code.
static void Main(string[] args)

        {

            //Ref variable should initialize inside CALLING method

            int a =10;

            //Out variabe no need to initialize inside calling method

            int b;

            Method1(ref a,out b);



        }



        private static void Method1(ref int a,out int b)

        {

            //Out variable should initialize inside CALLED method

            b = 200;

            a = 100;



        }
Code Alone8y ago
Hi Mukesh,

You can refer below articles :

https://www.c-sharpcorner.com/UploadFile/0c1bb2/ref-and-out-parameters-in-C-Sharp/

https://www.c-sharpcorner.com/UploadFile/mahakgupta/working-with-ref-and-out-parameter-in-C-Sharp/