# Java 程序：計算矩形面積 > 原文： [https://beginnersbook.com/2014/01/java-program-to-calculate-area-of-rectangle/](https://beginnersbook.com/2014/01/java-program-to-calculate-area-of-rectangle/) 在本教程中，我們將看到如何**計算矩形面積**。 **程序 1：** 用戶將在程序執行期間提供長度和寬度值，并根據提供的值計算面積。 ```java /** * @author: BeginnersBook.com * @description: Program to Calculate Area of rectangle */ import java.util.Scanner; class AreaOfRectangle { public static void main (String[] args) { Scanner scanner = new Scanner(System.in); System.out.println("Enter the length of Rectangle:"); double length = scanner.nextDouble(); System.out.println("Enter the width of Rectangle:"); double width = scanner.nextDouble(); //Area = length*width; double area = length*width; System.out.println("Area of Rectangle is:"+area); } } ``` 輸出： ```java Enter the length of Rectangle: 2 Enter the width of Rectangle: 8 Area of Rectangle is:16.0 ``` **程序 2：** 在上述程序中，將要求用戶提供長度和寬度值。如果您不需要用戶交互并且只想在程序中指定值，請參閱以下程序。 ```java /** * @author: BeginnersBook.com * @description: Calculation with no user interaction */ class AreaOfRectangle2 { public static void main (String[] args) { double length = 4.5; double width = 8.0; double area = length*width; System.out.println("Area of Rectangle is:"+area); } } ``` 輸出： ```java Area of Rectangle is:36.0 ```