5.日期对象的格式化和解析
格式化:
Date date = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss E");
String time = sdf.format(date);
System.out.println(time);
解析:
String time = "2000-10-10";
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Date date = sdf.parse(time);
System.out.println(date);
6.你来到这个世界有多少天
class Demo {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println("请输入您的出生日期(2000-10-10):");
String start = sc.nextLine();
System.out.println("请输入您现在的日期(2018-04-24):");
String now = sc.nextLine();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Date dateStart = sdf.parse(start);
Date dateNow = sdf.parse(now);
int dayNum = (dateNow.getTime() - dateStart.getTime()) / 1000 / 60 / 60 / 24;
System.out.println(dayNum);
}
}
7.Calendar类
Calendar由于是抽象类
获取对象的方法:
Calendar c = Calendar.getInstance();
c.set(参数);
c.add(参数);
c.get(参数);
8.Integer
是int类型的包装类
具有自动装箱拆箱的新特性
装箱:Integer in = new Integer(1);
拆箱:Integer in new Integer(10);
int i = in.intValue();
Integer integer = 10;
9.String的切割功能
String s = "C:\\aaa\\bbb\\c.txt";
String[] strs = s.split("\\\\");
System.out.println(Arrays.toString(strs));