Shulou(Shulou.com)06/02 Report--

This article will explain in detail what the four C# parameter types are, and the content of the article is of high quality, so the editor will share it with you for reference. I hope you will have some understanding of the relevant knowledge after reading this article.

There are four types of C# parameters:

Value Typ

Reference type

Output type

Array parameter

C# parameter type (1): value parameter

The so-called value parameter is that when the value is passed to the method, the compiler makes a copy of the value of the argument and passes the copy to the method. The result is that the called method will not modify the value of the argument, which ensures the security of the actual value. When calling the method, if the parameter type is the value type, you must ensure that the argument type is also the data of the value type.

Example:

Public class MyClass {public MyClass () {/ TODO: add constructor logic / /} public void ChangeValue (string value) {value = "Value is Changed!";}} here

-

String value = "Value"

Response.Write (value+ "

")

MyClass mc = new MyClass ()

Mc.ChangeValue (value)

Response.Write (value)

Effect:

C# parameter type (2): reference parameter

Use the ref keyword to pass parameters by reference. Any changes made to the parameters in the method will be reflected in the variable when it needs to be passed back to the calling method. If the ref keyword is used, the ref keyword must be used explicitly when the method is defined and called.

Pay attention to the use of ref!

Example:

Public class MyClass {public MyClass () {/ TODO: add constructor logic / /} public void ChangeValue (ref string value) {value = "Value is Changed!";}} here

-

String value = "Value"

Response.Write (value+ "

")

MyClass mc = new MyClass ()

Mc.ChangeValue (ref value)

Response.Write (value)

Effect:

C# parameter type (3): output parameter

Using the out keyword for reference passing, which is very long-lasting with the ref keyword, the difference is that ref requires variables to be initialized before passing. If the out keyword is used, the method definition and call must explicitly use the out keyword.

Example:

Public class MyClass {public MyClass () {/ TODO: add constructor logic / /} public void ChangeValue (out string value) {value = "Value is Changed!";}} here

-

String value; MyClass mc = new MyClass (); mc.ChangeValue (out value); Response.Write (value)

Effect:

C# parameter type (4): array parameter

The array parameter is the declaration params keyword, which is used to specify the method parameter where the number of parameters varies.

No other parameters are allowed after the params keyword in the method declaration, and only one params keyword is allowed in the method declaration.

Example:

Public class MyClass

{

Public MyClass ()

{

/ /

/ / TODO: add constructor logic here

/ /

}

Public void ChangeValue (params string [] value)

{

Foreach (string s in value)

{

HttpContext.Current.Response.Write (s + ")

")

}

}

}

-

String value1 = "Value1"; string value2 = "Value2"; MyClass mc = new MyClass (); mc.ChangeValue (value1, value2)

Effect:

In addition:

Parameters of the array type:

Array types are data of reference types, so they should also be classified as reference types.

Public class MyClass {public MyClass () {/ TODO: add constructor logic / /} public void ChangeValue here (string [] value) {value [0] = "This is Value0,Changed!";}}

-

String [] value = {"Value1", "Value2"}

Response.Write (value [0] + "

")

MyClass mc = new MyClass ()

Mc.ChangeValue (value)

Response.Write (value [0] + "

")

Effect:

Note:

The difference between ref and out:

Parameters passed to ref parameters must be initialized, while out parameters do not have to be initialized before being passed.

On what the four C# parameter types are shared here, I hope the above content can be of some help to you, can learn more knowledge. If you think the article is good, you can share it for more people to see.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.