java之字符串学习记录

public class StringDemo {

public static void main(String[] args) {

//静态初始化字符串

String s1 = "hello china!";

String s3 = "Hello China!";

System.out.println(s1);

//动态初始化字符串

String s2 = new String("hello china!,china,china");

String s4 = new String("hello china!");

String s5 = "hello Japan";

String s6 = "Hey,"; //Hey,hello china!

String s7 = "北京|上海|南京|武汉|成都";

System.out.println(s1==s3);//true

System.out.println(s2==s4);//false

System.out.println(s2.equals(s4));//true

System.out.println(s1.charAt(6));//获得字符‘c‘

//返回0：s1==s5, 负数  s1<s5  正数 s1>s5

System.out.println(s1.compareTo(s5));

System.out.println(s6.concat(s1));

System.out.println(s6+s1);

System.out.println(s1.contains("china"));//true

System.out.println(s1.contains("japan"));//false

byte[] arr = s1.getBytes();

System.out.println(s2.indexOf("china"));

System.out.println(s2.lastIndexOf("china"));

String[] citys = s7.split("\\|");

for(int i=0;i<citys.length;i++)

{

System.out.println(citys[i]);

}

StringTokenizer st = new StringTokenizer(s7,"|");

System.out.println("-------------------");

while(st.hasMoreElements())

{

System.out.println(st.nextElement());

}

System.out.println(s1.substring(6,s1.length()-1));

System.out.println(s1.toUpperCase());

System.out.println(s3.toLowerCase());

}

}