字符串方法
package com.company;
import java.nio.charset.StandardCharsets;
public class string {
public static void main(String[] args) {
System.out.println("ok");
//replace 替换 例 str.replace('a','b')
//str.replaceAll 替换所有 例: repleceAll("\\d+",",").replaceAll("^,|^,$",| ""),
// 后面一个正意思是开头有逗号或者开头有$,用空位置替切换。
//boolean me = str.metches("\\d+"); 判断是不是数字
String tel = "0557-23455";
boolean result = tel.matches("0577-\\d{7,8}");
System.out.println(result);
//切片用法 split;
String str = "hello|word|jaca";
String[] strs = str.split("\\|");
for(int i= 0; i< strs.length; i++){
System.out.println(strs[i]);
}
//举例二:
String str2 = "hello.world.java";
String[] strs2 = str2.split("\\.");
for(int i = 0; i< strs.length; i++){
System.out.println(strs2);
}
}
//字符转数字 int num = Integer.parseInt(Str1); 数字转字符 String.valueOf(num);
//数字转字符也可以用"" 强转 String str3 = mum+"";
//char[] charArr = str1.toCharArray();
//new一个字节如何成为字符 char[] arr = new char[] {'1','2'};
char[] arr = new char[] {'1','2'};
String str2 = new String(arr);
//如何将字节转在字条符
public void test2(){
[String str1 = "abc123";
byte[] bytes = str1.getBytes();
byte[] gbks=str1.getBytes("gbk");//一个汉字占二位,UTF-8占三位 编码行为,将字节变成能看懂的叫解码,new String(bytes)
//
System.out.println(Arrays.toString(bytes));
}
}