摘要：
public class DemoText { public static void main(String[] args) { fun(); } public static void fun(){ String s="heLLo"; String s2=s.substring(0,1); Syst 阅读全文
摘要：
public class DemoText { public static void main(String[] args) { fun1(); } public static void fun1(){ String s = "hello word Ok Yes hello hello"; int 阅读全文