package test;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
public class Test {
public static void main(String[] args) throws IOException
{
String a = null;
doHello(a="Hello world");//这里的参数是重点
}
private static void doHello(String string) {
System.out.println(string);
}
}