String 常用Api

package com.itheima;

public class string {
    public static void main(String[] args) {
        String s1 = "qwertyuio";
        String s3 = "QWErtyuio";
        System.out.println(s1.equals(s3));
        //进行比较，不区分大小写
        System.out.println(s1.equalsIgnoreCase(s3));
        //长度
        System.out.println(s1.length());
        //索引字符
        System.out.println(s1.charAt(1));
        //打印字符串
        for (int i = 0; i < s1.length(); i++) {
            System.out.print(s1.charAt(i));
        }
        //将字符串转换为字符数组
        char[] chars = s1.toCharArray();
        //字符串子串
        System.out.println(s1.substring(4));
        System.out.println(s1.substring(1, 5));
        //替换字符串，String不可变性
        String replace = s1.replace("q", "e");
        System.out.println(replace);
        System.out.println(s1);
        //包含,返回bool
        System.out.println(s1.contains("qwe"));
        //判断字符串是否以指定字符串开头
        System.out.println(s1.startsWith("qwer"));
        String s4 = "a,b,c,d";
        String[] s5 =s4.split(",");
        for (int i = 0; i < s5.length; i++) {
            System.out.print(s5[i]+"\t");
        }
    }
}