java - 有没有更好的方法 - Java 条件语句

Question

我刚刚开始编程。我为我的编程课编写了这个类(class)。它从老师给我们的驱动程序中提取参数，然后将比例形状放入用户选择的 jPanel 象限中。它工作正常，但我想知道是否有更有效和更干净的方式来编写代码。老师没有对早期的项目提供任何反馈，所以我想在这里问一下。感谢您的帮助。

import java.awt.*;

 public class LearnGraphics {


public static void drawRectangle(Graphics g, int size, String cord_x, String cord_y) {
        int longside = size / 4;
        int shortside = size / 8;
        int x = 0;
        int y = 0;
        if(cord_x.equals("top")&&cord_y.equals("right")) {  
            x = size-(size/3);
            y = size/8;
        }
        if(cord_x.equals("top")&&cord_y.equals("left")) {  
            x = size/12;
            y = size/8;
        }
        if(cord_x.equals("bottom")&&cord_y.equals("right")) {  
            x = size-(size/3);
            y = size-(size/4);
        }
        if(cord_x.equals("bottom")&&cord_y.equals("left")) {  
            x =  size/12;
            y = size-(size/4);
        }
        g.drawRect(x, y, longside, shortside);

    }

public static void drawLine(Graphics g, int size, String cord_x, String cord_y) {

    int x = 0;
    int y = 0;
    int x1 = 0;
    int y1 = 0;
    if(cord_x.equals("top")&&cord_y.equals("right")) {  
        x = size/12;
        y = size/6;
        x1 = size/3;
        y1 = size/6;
    }
    if(cord_x.equals("top")&&cord_y.equals("left")) {  
        x = (size/2)+(size/6);
        y = size/6;
        x1 = size-(size/12);
        y1 = size/6;
    }
    if(cord_x.equals("bottom")&&cord_y.equals("right")) {  
        x = size/12;
        y = size-(size/6);
        x1 = size/3;
        y1 = size-(size/6);
    }
    if(cord_x.equals("bottom")&&cord_y.equals("left")) {  
        x = (size/2)+(size/6);
        y = size-(size/6);
        x1 = size-(size/12);
        y1 = size-(size/6);
    }
    g.drawLine(x, y, x1, y1 )  
}
public static void drawOval(Graphics g, int size, String cord_x, String cord_y) {
    int longside = size / 4;
    int shortside = size / 8;
    int x = 0;
    int y = 0;
    if(cord_x.equals("top")&&cord_y.equals("right")) {  
        x = size-(size/3);
        y = size/8;
    }
    if(cord_x.equals("top")&&cord_y.equals("left")) {  
        x = size/12;
        y = size/8;
    }
    if(cord_x.equals("bottom")&&cord_y.equals("right")) {  
        x = size-(size/3);
        y = size-(size/4);
    }
    if(cord_x.equals("bottom")&&cord_y.equals("left")) {  
        x =  size/12;
        y = size-(size/4);
    }
    g.drawOval(x, y, longside, shortside);    
   }
  }

Answer 1

如果你执行if-else语句，那么一旦你输入其中一个语句，你就不会再执行if语句，这样会更高效，而且你不会两次询问相同的条件

public static void drawRectangle(Graphics g, int size, String cord_x, String cord_y) {
    int longside = size / 4;
    int shortside = size / 8;
    int x = 0;
    int y = 0;
    if(cord_x.equals("top")) {  
        if(cord_y.equals("right"))
        {
           x = size-(size/3);
           y = size/8;
        }
        else
        {
           if(cord_y.equals("left"))
           {
               x = size/12;
               y = size/8;
           }
        }
    }
    else
    {

        if(cord_x.equals("bottom")) {  
           if(cord_y.equals("right"))
           {
              x = size-(size/3);
              y = size-(size/4);
           }
           else
           {
              if(cord_y.equals("left"))
              {
                 x =  size/12;
                y = size-(size/4);
              }
           }
        }
    }
    g.drawRect(x, y, longside, shortside);

}

除此之外，目前没有什么可担心的，因为现代计算机速度非常快，而且这段代码并不长，所以它会很快