Java 日历 add()方法及实例

Calendar类中的 add()方法用于根据日历的规则，从给定的日历字段（int field）中增加或减少特定的时间（int amt）。

语法

public abstract void add(int field , int amt)

参数： 该方法需要两个参数。

返回值： 该方法不返回任何值。

例1 :

// Java Program to Illustrate add() Method// of Calendar class // Importing required classesimport java.util.Calendar; // Main classpublic class CalendarClassDemo {     // Main driver method    public static void main(String args[])    {        // Creating a Calendar class object        Calendar calndr = Calendar.getInstance();         // Displaying the current date        // using getTime() method        System.out.println("Current Date: "                           + calndr.getTime());         // Adding 50 days to the        // Current Calendar        // using add() method        calndr.add(Calendar.DATE, 50);         // Displaying the date now using getTime() method        System.out.println("After 50 days: "                           + calndr.getTime());         // Subtracting 6 months from        // the Current calendar        calndr.add(Calendar.MONTH, -6);         // Displaying the date now using getTime() method        System.out.println("6 months ago it was: "                           + calndr.getTime());         // Subtracting 2 year from        // the Current calendar        calndr.add(Calendar.YEAR, -2);         // Displaying the date now using getTime() method        System.out.println("2 years ago it was: "                           + calndr.getTime());    }}

输出

Current Date: Tue Feb 12 10:54:21 UTC 2019After 50 days: Wed Apr 03 10:54:21 UTC 20196 months ago it was: Wed Oct 03 10:54:21 UTC 20182 years ago it was: Mon Oct 03 10:54:21 UTC 2016

例2 :

// Java Program to Illustrate add() Method// of Calendar class // Importing required classesimport java.util.Calendar; // Main classpublic class GFG {     // Main driver method    public static void main(String args[])    {        // Creating a calendar object        Calendar calndr = Calendar.getInstance();         // Displaying the current date        // using getTime() method        System.out.println("Current Date: "                           + calndr.getTime());         // Adding 30 days to the current calendar        // using add() method        calndr.add(Calendar.DATE, 30);         // Printing the corresponding date        System.out.println("After 30 days: "                           + calndr.getTime());         // Subtracting 3 months from the current calendar        calndr.add(Calendar.MONTH, -3);         // Printing the corresponding date        System.out.println("3 months ago it was: "                           + calndr.getTime());         // Subtracting 10 years from        // the Current calendar        calndr.add(Calendar.YEAR, -10);         // Printing the corresponding date        System.out.println("10 years ago it was: "                           + calndr.getTime());    }}

输出

Current Date: Tue Feb 12 10:54:24 UTC 2019After 30 days: Thu Mar 14 10:54:24 UTC 20193 months ago it was: Fri Dec 14 10:54:24 UTC 201810 years ago it was: Sun Dec 14 10:54:24 UTC 2008