C＃程序中return语句的目的是什么

Question

What is the purpose of a return statement.

Example :

Class Sample 
{
    public static int Main()
    {
      System.Console.WriteLine("Hello World");
      return 0;
    } 
}

In the above program what actually is being returned. Is it returning integer value 0 ? Does this help in the flow of program execution

(This might be a stupid question, but I am eager to know.)

Answer 1

The exit code of the application is set to the value returned from Main. This can be used to communicate to the calling application if there was an error or everything succeeded when running the child application.

When running from the console window, the last exit code is set in the environment variable which can be used to control the execution of a batch file for example.

See the following MSDN entry for more info and an example. http://msdn.microsoft.com/en-us/library/0fwzzxz2.aspx

Answer 2

The exit code of an application (return from main) can be queried in the operating system or in batch programs. In windows, it can be processed in a batch using the %errorlevel% environment var.

@echo off
yourpgrogram
echo Your program returned %errorlevel%

would brint out Your program returned 0

hth

Mario

Answer 3

From the Main() method, the value returned will affect the program's exit code . From MSDN :

... returning an integer enables the program to communicate status information to other programs or scripts that invoke the executable file.

Answer 4

return 0是执行中没有错误的约定