java基础篇01

一、字符串的学习

package StringLearn;
public class StringTest {
    public static void main(String[] args) {
        //String类型存在jvm的方法区，常量池里面
        String s1 = "abcdef";
        //拼接产生新的字符串常量
        String s2 = "abcdef" + "xy";

        //new 对象时一定在堆内存里开辟空间
        String s3 = new String("xy");

        byte[] bytes01 = {97, 98, 99, 100};
        String string01 = new String(bytes01);
        System.out.println(string01); //abcd
        System.out.println(string01.toString());
        String string02=new String(bytes01,1,3);
        System.out.println(string02);//bcd

        char char01="中国人".charAt(0);
        System.out.println(char01);//中

        int result01="abc".compareTo("abd");//相等是0，前大后小是1，反之-1
        System.out.println(result01);

        System.out.println("My name is ADC".contains("ADC"));
        System.out.println("My name is ADC".endsWith("ADC"));
        System.out.println("My name is ADC".startsWith("ADC"));

        System.out.println("abc".equalsIgnoreCase("Abc"));//ture
        //字符串切割的方法
        String []string03="2000-01-01".split("-");
        for (int i=0;i