how to truncate decimals in java

To truncate decimals in Java, you can use the Math.floor method to round down to the nearest integer, or the Math.round method to round to the nearest integer.

Here's an example of how you can use the Math.floor method to truncate decimals:

public class Main {
    public static void main(String[] args) {
        double num = 123.456;

        // Truncate the decimal part of the number
        double truncated = Math.floor(num);

        System.out.println("Truncated: " + truncated);
    }
}

This code will truncate the decimal part of the number 123.456 and print the result to the console. The output of this code will be:

Truncated: 123.0

Here's an example of how you can use the Math.round method to round a number to the nearest integer:

public class Main {
    public static void main(String[] args) {
        double num = 123.456;

        // Round the number to the nearest integer
        long rounded = Math.round(num);

        System.out.println("Rounded: " + rounded);
    }
}

This code will round the number 123.456 to the nearest integer and print the result to the console. The output of this code will be:

Rounded: 123

Note that the Math.floor method will always round down to the nearest integer, while the Math.round method will round to the nearest integer using standard rounding rules (i.e. it will round up for numbers with a decimal value of 0.5 or greater).

If you want to truncate decimals to a specific number of decimal places, you can use the DecimalFormat class from the java.text package.

Here's an example of how you can use the DecimalFormat class to truncate decimals to 2 decimal places:

import java.text.DecimalFormat;

public class Main {
    public static void main(String[] args) {
        double num = 123.456789;

        // Truncate the number to 2 decimal places
        DecimalFormat df = new DecimalFormat("#.00");
		System.out.println(df.format(num));
	}
}