ZhouXin的专栏

jdk环境配置写下来，免得以后又忘。。。 安装JDK1.5后，环境变量修改：    1 JAVA_HOME       jdk路径    2 path       JAVA_HOME/bin    3 classpath       ..,. 测试：public class hello{  public static void main(String a

substringpublic String substring(int beginIndex)Returns a new string that is a substring of this string. The substring begins with the character at the specified index and extends to the end