Year atMonth(int) method in Java

The atMonth(int) method of Year class in Java combines the current year object with a month passed as parameter to it to create a YearMonth object.

Syntax:

public YearMonth atMonth(int month)

Parameter: This method accepts a single parameter month. It is the month-of-year to use. It takes an integer value between 1 and 12 and cannot be NULL.

Return Value: It returns a YearMonth object formed by the current year object and a valid month passed as parameter to the function.

Exception: This method throws a DateTimeException, if the month passed to it as parameter is invalid.

Below programs illustrate the atMonth(int) method of Year in Java:
Program 1:

// Program to illustrate the atMonth(int) method

import java.util.*;
import java.time.*;

public class GfG {
    public static void main(String[] args)
    {
        // Creates a Year object
        Year thisYear = Year.of(2017);

        // Creates a YearMonth with this
        // Year object and Month passed to it
        YearMonth yearMonth = thisYear.atMonth(4);

        System.out.println(yearMonth);
    }
}

Output:

2017-04

Program 2: To illustrate Exception.

// Program to illustrate the atMonth(int) method

import java.util.*;
import java.time.*;

public class GfG {
    public static void main(String[] args)
    {
        // Creates a Year object
        Year thisYear = Year.of(2018);

        try {
            // Creates a YearMonth with this
            // Year object and Month passed to it
            YearMonth yearMonth = thisYear.atMonth(16);

            System.out.println(yearMonth);
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}

Output:

java.time.DateTimeException: Invalid value for MonthOfYear (valid values 1 - 12): 16

Reference: https://docs.oracle.com/javase/8/docs/api/java/time/Year.html#atMonth-