Java连接字符串。

import java.lang.*;

   public class StringDemo {

      public static void main(String[] args) {



      // print str1

      String str1 = "self";

      System.out.println(str1);



      // print str2 concatenated with str1

      String str2 = str1.concat(" learning");

      System.out.println(str2);



      // prints str3 concatenated with str2(and str1)

      String str3 = str2.concat(" center");

      System.out.println(str3);

   }

}