W3School TIY Editor

public class Main {

  public static void main(String[] args) {

    // 创建整型变量

    int length = 4;

    int width = 6;

    int area;

​

    // 计算矩形面积

    area = length * width;

​

    // 打印变量

    System.out.println("长度为: " + length);

    System.out.println("宽度为: " + width);

    System.out.println("矩形面积为: " + area);

  }

}