Java Calendar.before()用法及代碼示例

java.util.Calendar.before()是java.util包Calendar類中的方法。如果此Calendar表示的時間早於when對象表示的時間，則該方法返回true。如果不是這種情況，則返回false。

用法:

public boolean before(Object when)

Where, when is the Object 
that is to be compared.

下麵是一些示例，以更好的方式理解Calendar.before()函數的實現。

示例1:

// Implementation to show the usage 
// of before(Object when) method of 
// Calendar class 
import java.util.*; 
  
class GFG { 
  
    public static void main(String[] args) 
        throws InterruptedException 
    { 
  
        // creating calendar object 
        Calendar cal_obj1 = Calendar.getInstance(); 
  
        // printing current date 
        System.out.println("Time 1 : " + cal_obj1.getTime()); 
  
        // sleep for 3 seconds 
        Thread.sleep(3000); 
  
        // creating Calendar object 
        Calendar cal_obj2 = Calendar.getInstance(); 
  
        // printing current date 
        System.out.println("Time 2 : " + cal_obj2.getTime()); 
  
        // checking if 1st date is before 2nd date 
        // and printing the result 
        System.out.println(cal_obj1.before(cal_obj2)); 
    } 
}

輸出：

Time 1 : Wed Feb 28 15:43:19 IST 2018
Time 2 : Wed Feb 28 15:43:22 IST 2018
true

示例2:

// Implementation to show the usage 
// of before(Object when) method of 
// Calendar class 
import java.util.*; 
  
class GFG { 
  
    public static void main(String[] args) 
    { 
  
        // creating calendar objects 
        Calendar cal_obj1 = Calendar.getInstance(); 
        Calendar cal_obj2 = Calendar.getInstance(); 
  
        // displaying the current date 
        System.out.println("Current date is : " + cal_obj1.getTime()); 
  
        // changing year in cal_obj2 calendar 
        cal_obj2.set(Calendar.YEAR, 2010); 
  
        // displaying the year 
        System.out.println("Year is " + cal_obj2.get(Calendar.YEAR)); 
  
        // check if calendar date is before current date 
        System.out.println("Result : " + cal_obj1.before(cal_obj2)); 
    } 
}

輸出：

Current date is : Wed Feb 28 15:50:16 IST 2018
Year is 2010
Result : false

示例3:

// Implementation to show the usage 
// of before(Object when) method of 
// Calendar class 
import java.util.*; 
  
class GFG { 
  
    public static void main(String[] args) 
    { 
  
        // creating calendar objects 
        Calendar cal_obj1 = Calendar.getInstance(); 
        Calendar cal_obj2 = Calendar.getInstance(); 
  
        // displaying the current date 
        System.out.println("Current date is : " + cal_obj1.getTime()); 
  
        // changing year in cal_obj2 calendar 
        cal_obj2.set(Calendar.YEAR, 2025); 
  
        // displaying the year 
        System.out.println("Year is " + cal_obj2.get(Calendar.YEAR)); 
  
        // check if calendar date is before current date 
        System.out.println("Result : " + cal_obj1.before(cal_obj2)); 
    } 
}

輸出：

Current date is : Wed Feb 28 16:15:55 IST 2018
Year is 2025
Result : true

相關用法

注：本文由純淨天空篩選整理自Sahil_Bansall大神的英文原創作品 Calendar.before() method in Java。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。