c# param keyword

Question

What is the real use of param keyword in c#? Please explain in detail with example.

Vulpes · Answer

You're not allowed to specify a default value for a parameter array (not even 'null') which rules out their use as optional parameters. However, you can pass no argument at all in which case it's assumed that the parameter arrray has been set to an array with no elements i.e. a zero length array. As Anupam said, you can use pass a parameter array as a named argument but only if you pass an entire array, not a series of individual arguments. So: // the following is not allowed at all void MyMethod(params string[] sa = null) { } // the following is, of course, allowed void MyMethod(params string[] sa) { } and can be called with: MyMethod(); // new string[0] is effectively passed or it can be called with: MyMethod(sa: new string[]{"a", "b"}); but it can't be called with: MyMethod(sa[0] : "a", sa[1] : "b"});

Gurunatha Dogi · Answer

Check this link below to understand use of params parameter in c-sharp http://www.onlinebuff.com/article_understand-params-parameter-with-an-example-in-c_47.html

Anupam Singh · Answer

you can use param as named parameter like : MyMethod (str : new string[]{"str1","str2"}) . I believe not but not sure about it could be optional or not :(. .

Akhil Mittal · Answer

Can param be passed as optional or named parameter?

Anupam Singh · Answer

Hi Akhil, param is very useful in C# . We basically use it with method parameters. like MyMethod(param string srr) . uses are : In this method you can pass parameter like MyMethod(string[]) or MyMethod("string1","string2","string3"). means we can use parameters as an array as well. Conclusion is the same method will work like as MyMethod(string str1,string str2,string str3) and MyMethod(string[] str) so your one method MyMethod(param string srr) is working like the same as 1. MyMethod(string str1,string str2,string str3) 2. MyMethod(string[] str) Hope it helps.

Abhay Shanker · Answer

you can also check the link http://www.msdotnet.co.in/2013/04/params-keyword-in-c.html#.U4H4EvmSwcA

Lakshmanan Sethu · Answer

pls refer http://www.dotnetperls.com/params

Bhabani Prasad · Answer

http://msdn.microsoft.com/en-us/library/w5zay9db.aspx

c# param keyword

Answers (8)