String常用方法小例子

package com.fjz.string;

public class StringTest {
	public static void main(String[] args) {
		String str = new String("asdfzxcjkdncnjad");
		String chan = new String("asdfZxcjKDncNjAd");
		String strcon = "";
		String strlist = "I am a good student";
		String strlist1 = " i am a boy ";
		String str2 = "asdzxcasd";
		
		int strlength = str.length(); //1.字符串长度
		
		char ch = str.charAt(4); //2.字符串某一位置的字符z,索引为4
		
		String strsub1 = str.substring(2, 6); //3.截取字符dfzx
		String strsub2 = str.substring(2); //dfzxcjkdncnjad
		
		int a = str.compareTo(chan); // 4.字符串比较a >0;
		int b = str.compareToIgnoreCase(chan); //b = 0
		boolean c = str.equals(chan); //c :false
		boolean d = str.equalsIgnoreCase(chan);//d :true
		
		strcon = strcon.concat("aa");//5.字符串连接aa
		
		int e = strlist.indexOf('a');//6.字符串中单个字符查找a = 2
		int f = strlist.indexOf("good");//b =7
		int g = strlist.indexOf("w",2);//c = -1
		int h = strlist.lastIndexOf("a");//d = 5
		int i = strlist.lastIndexOf("a",3);//e = 2
		
		String strlow = chan.toLowerCase();//7.转换为小写asdfzxcjkdncnjad
		String strupp = str.toUpperCase();//转换为大写ASDFZXCJKDNCNJAD
		
		String strtrim = strlist1.trim();//8.去除两边空格，不去除中间的i am a boy
		
		String strrep1 = str.replace('a','g');//9，替换字符str1 = "gsdzxcgsd"
		String strrep2 = str.replace("asd","fgh");//str2 = "fghzxcfgh"
		String strrep3 = str.replaceFirst("asd","fgh");//str3 = "fghzxcasd"
		String strrep4 = str.replaceAll("asd","fgh");//str4 = "fghzxcfgh"
		
	}
}