formtriagle.java

是<java程序设计>的课后作业2-8源码.可以供初学者参考,作了解java基础语法所用.

/**
 * @(#)FormTriagle.java
 *
 *
 * @author 
 * @version 1.00 2009/3/1
 */
 import javax.swing.JOptionPane;

public class FormTriagle {
        
    /**
     * Creates a new instance of <code>FormTriagle</code>.
     */
    public FormTriagle() {
    }
    
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        //提示用户输入,三边
        /*String StringEdge1=JOptionPane.showInputDialog(null,"请输入第一条边的长度:",
        "Program 2.9 input",JOptionPane.QUESTION_MESSAGE);
        String StringEdge2=JOptionPane.showInputDialog(null,"请输入第二条边的长度:",
        "Program 2.9 input",JOptionPane.QUESTION_MESSAGE);
        String StringEdge3=JOptionPane.showInputDialog(null,"请输入第三条边的长度:",
        "Program 2.9 input",JOptionPane.QUESTION_MESSAGE);*/
        
        String[] StringEdges=new String[3];
        double[] doubleEdges=new double[3];
        for(int i=0;i<3;i++){
        StringEdges[i]=JOptionPane.showInputDialog(null,"请输入第"+(i+1)+"条边的长度:",
        "Program 2.9 input",JOptionPane.QUESTION_MESSAGE);
        doubleEdges[i]=Double.parseDouble(StringEdges[i]);
        }
     
        //验证边长的正负符号
        for(int i=0;i<3;i++)
        {
        	if(doubleEdges[i]<=0)
        	{
        		JOptionPane.showMessageDialog(null,"Can edges "+doubleEdges[0]+", "
        			+doubleEdges[1]+" and "+doubleEdges[2]+" form a triagle? false",
        			"Program 2.9 out",JOptionPane.QUESTION_MESSAGE);
        		return;
        	}
        				
        }
        
        //验证两边和是否大于第三边
        
        	for(int i=0;i<3;i++)
        {
        	if(doubleEdges[i]+doubleEdges[(i+1)%3]<=doubleEdges[(i+2)%3])
        	{
        		JOptionPane.showMessageDialog(null,"Can edges "+doubleEdges[0]+", "
        			+doubleEdges[1]+" and "+doubleEdges[2]+" form a triagle? false",
        			"Program 2.9 out",JOptionPane.QUESTION_MESSAGE);
        		return;
        	}
        				
        }
        
        JOptionPane.showMessageDialog(null,"Can edges "+doubleEdges[0]+", "
        			+doubleEdges[1]+" and "+doubleEdges[2]+" form a triagle? true",
        			"Program 2.9 out",JOptionPane.QUESTION_MESSAGE);
        return;
        
        
    }
}