Difference between ref and out parameter

Ganeshji
Posted by in C# category on for Beginner level | Points: 250 | Views : 11067 red flag
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Recently, I have come across a query in a forum. The query was something like 'difference between ref and out parameters'. Hence, I have just tried to point out the difference between the two.

Introduction

We can pass ref and out parameters through the methods as arguments.



Out Parameter

In case of out parameter , the caller method need not assign a value to the out parameter. Instead the callee method is responsible to assign value in the out parameter.

Let me show u examples:

Sending single unassigned variable using out parameter.

Output

 

 

Sending multiple unassigned variables using out parameter.

 

Output

 

Ref Parameter

Whereas, in case of ref parameter, the caller method must assign a value to the ref parameter. Here the callee method may change the value of the ref parameter.  

Sending single assigned variable using ref parameter.

Output

 

Sending multiple assigned variables using ref parameter.

Output

 

Sending unassigned variable using ref paramter gives an error.

Error Message on trying to send unassigned variable using ref parameter.

 

Conclusion

Happy Reading!

Reference

http:// www. dotnetspider.com/forum/156002-What-difference-between-out-ref-C.aspx
http:// www. c-sharpcorner. com/UploadFile/mahesh/out_and_ref11112005002102AM/out_and_ref.aspx
http:// dotnetperls.com/ref
http:// dotnetrobert .com/?q=node/209

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About the Author

Ganeshji
Full Name: Zinnia Sarkar
Member Level:
Member Status: Member
Member Since: 7/24/2010 12:50:40 PM
Country: India
Regards, Ganeshji


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Comments or Responses

Posted by: Ck.kislay on: 1/21/2011 | Points: 25
Only Out parameter is sufficient to achieve the goal.

Let me know any specific reason so that .net framework provde the ref parameter??

Thanks,
Chandan
Posted by: Ganeshji on: 1/21/2011 | Points: 25
A method parameter can be modified by ref.
Thnx,
Zinnia Sarkar
Posted by: Vijayakumarp on: 3/19/2012 | Points: 25
Thanks for great article..

Only i found the difference between these two parameters(out,ref) that the ref parameter variable should be assigned value..

Vijayakumar
Posted by: Ganeshji on: 3/19/2012 | Points: 25
Thanks Vijayakumarp!

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