Java中的 GregorianCalendar hashCode() 方法

Java .util.GregorianCalendar.hashCode()是Java中的一个内置函数，它为此GregorianCalendar 实例生成哈希码。

句法：

public int hashCode()

参数：此函数不接受任何参数。

返回值：此函数返回一个整数值，表示此GregorianCalendar 实例的哈希码。

例子：

Input : Thu Jul 24 00:53:29 UTC 1997
Output : 2121703905

Input : Tue Jul 24 00:54:11 UTC 2018
Output : -909136554

下面的程序说明了Java.util.GregorianCalendar.hashCode()函数：
方案一：

// Java Program to illustrate hashCode() function
// of GregorianCalendar class
  
import java.io.*;
import java.util.*;
  
class GFG {
     public static void main(String[] args) {
      
      // Create a new calendar
      GregorianCalendar c = (GregorianCalendar) 
                GregorianCalendar.getInstance();
  
      // Display the current date and time
      System.out.println("Current Date and Time : "
                                    + c.getTime());
        
      // Display hashcode for this calendar
      System.out.println("Hash Code:" + c.hashCode());
   }
}

输出：

Current Date and Time : Fri Jul 27 11:43:16 UTC 2018
Hash Code:-612105832

方案二：

// Java Program to illustrate hashCode() function
// of GregorianCalendar class
  
import java.io.*;
import java.util.*;
  
class GFG {
     public static void main(String[] args) {
      
      // Create a new calendar
      GregorianCalendar c = (GregorianCalendar) 
                 GregorianCalendar.getInstance();
  
      // Display the current date and time
      System.out.println("Current Date and Time : "
                                     + c.getTime());
        
      c.add((GregorianCalendar.YEAR), -12);
      System.out.println("Modified Date and Time : "
                                    + c.getTime());
        
      // Display hashcode for this calendar
      System.out.println("Hash Code of the " + 
      "modified date and time:" + c.hashCode());
   }
}

输出：

Current Date and Time : Fri Jul 27 11:43:18 UTC 2018
Modified Date and Time : Thu Jul 27 11:43:18 UTC 2006
Hash Code of the modified date and time:-1346149059

参考： https: Java/util/GregorianCalendar.html#hashCode()