Java Calendar equals()用法及代碼示例

equals() 方法比較兩個對象是否相等，如果相等則返回 true。 equals() 方法在 Object 類中提供。因為對象類是java中所有其他類的超類。 Calendar 類繼承了 equals() 方法。它將此(當前日曆對象)日曆與指定的對象進行比較。當且僅當參數是同一日曆係統的 Calendar 對象，該對象在與此對象相同的 Calendar 參數下表示相同的時間值時，結果才為真。

用法

public boolean equals(Object object)

參數

對象：要比較的對象

它返回一個布爾值。

拋出

不要拋出任何異常。

例子1

import java.util.Calendar;
public class CalendarEqualsExample1 {
public static void main(String[] args) {
      // create a new calendar object
     Calendar cal1 =  (Calendar) Calendar.getInstance();
      // print the current date and time
      System.out.println("" + cal1.getTime());
      // create a second calendar object
        Calendar cal2 = (Calendar) Calendar.getInstance();
      // print cal2
      System.out.println("" + cal2.getTime());
      // compare the first and second calendar object
      System.out.println("Cal1 and Cal2 are equal:" + cal1.equals(cal2));
   }
}

輸出：

Wed Aug 01 02:31:56 PDT 2018
Wed Aug 01 02:31:57 PDT 2018
Cal1 and Cal2 are equal:false

例子2

import java.util.Calendar;
public class CalendarEqualsExample2 {
public static void main(String[] args) {
      // create a new calendar object
    Calendar cal1 =  (Calendar) Calendar.getInstance();
      // print the current date and time
      System.out.println("" + cal1.getTime());
      // create clone of first calendar object
      Calendar cal2 = (Calendar) (Calendar) cal1.clone();
      // print cal2
      System.out.println("" + cal2.getTime());
      // compare the first calendar object and cloned calendar object
      System.out.println("Cal1 and Cal2 are equal:" + cal1.equals(cal2));    
   }
}

輸出：

Wed Aug 01 02:34:20 PDT 2018
Wed Aug 01 02:34:20 PDT 2018
Cal1 and Cal2 are equal:true

例子3

import java.util.Calendar;
public class CalendarEqualsExample3 {
public static void main(String[] args) {
      // create a new calendar object
   Calendar cal1 =  (Calendar) Calendar.getInstance();
      // print the current date and time
      System.out.println("" + cal1.getTime());
      // create a clone of first calendar object
      Calendar cal2 = (Calendar) (Calendar) cal1.clone();
      // print cal2
      System.out.println("" + cal2.getTime());
      // change YEAR field of cloned calendar object
      cal2.add(Calendar.YEAR, 5);
      // compare the two calendars
      System.out.println("Cal1 and Cal2 are equal:" + cal1.equals(cal2));
   }
}

輸出：

Wed Aug 01 02:36:22 PDT 2018
Wed Aug 01 02:36:22 PDT 2018
Cal1 and Cal2 are equal:false

相關用法

注：本文由純淨天空篩選整理自 Java Calendar equals() Method。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。