How to round a number using Math.round() method in Java?

How to round numbers using Math.round() method in Java?

Overview:
The Math class in Java provides a series of convenient mathematical calculation methods, including a method called round(), which is used to round floating-point numbers. This article explains how to correctly use the Math.round() method to round numbers and provides corresponding code examples.

Specific steps:

1. Import the Math class:
   At the beginning of the code, you need to import the java.lang.Math class in order to use the round() in it method. This can be achieved by adding an import statement at the beginning of the code.

   Sample code:
   import java.lang.Math;

2. Call the Math.round() function:
   Where numbers need to be rounded , called using the Math.round() method. This method accepts a parameter of type double and returns a result of type long, representing the rounded integer value.

   Sample code:
   double num = 3.7;
   long roundedNum = Math.round(num);

3. Result output:
   You can The rounded results are printed for viewing.

   Sample code:
   System.out.println("The rounded result is: " roundedNum);

Full sample code:

import java.lang.Math;

public class RoundExample {
    public static void main(String[] args) {
        double num = 3.7;
        long roundedNum = Math.round(num);
        System.out.println("四舍五入后的结果为：" + roundedNum);
    }
}

Running results:

四舍五入后的结果为：4

Notes:

1. The round() method is rounded by rounding rules, that is, when the decimal part is greater than or equal to 0.5, the nearest integer part is taken Integer, if less than 0.5, take the nearest integer part minus one. Please make a judgment based on actual needs for specific selection rules.
2. The return result of the Math.round() method is of type long. If you need to obtain a result of type int, you can cast the result. For example: int roundedNum = (int)Math.round(num).

Summary:
This article briefly introduces how to use the Math.round() method in Java to round numbers. By importing the Math class, calling the round() method, and outputting the result, you can easily implement the rounding operation of floating point numbers. Using this method, numbers can be quickly and accurately rounded to meet specific business needs.

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