int,string,double类型转换

package com.lang;

public class DoubleTest {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        
        //double 和 Double 
        
//        int i = 5;
//        Integer ii = new Integer(5);
//        
        double d = 12.34;
        
        Double dou = new Double(d);
        Double dou1 = Double.valueOf(d);    
        //int iii = ii.intValue(); 
        double d1 = dou.doubleValue();
        
        
        //double和String之间
//        String s  = Integer.toString(i);
//        System.out.println(s);
        String s = Double.toString(d);
        
       // int iiii = Integer.parseInt(s);
         double d2 = Double.parseDouble(s);
//         
//       //String 和Integer的关系处理
//         //1.String转Integer
//         Integer iiiii = Integer.valueOf(s);
//         System.out.println(iiiii);
//         
//         //2.Integer转String
//         String ss = iiiii.toString();  
         Double d4 = Double.valueOf(s);
         String ss = d4.toString();
    }

}

 

package com.lang;

public class IntegerTest {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        
        //int 和 integer(int 的包装类)之间的转化
        
        //1. int转integer
        int i = 5;
        Integer ii = new Integer(5);
        
        //2. integer转int
        
        int iii = ii.intValue(); 
        System.out.println(iii);
        
        //int和String之间的转换
        //1. int转String
        String s  = Integer.toString(i);
        System.out.println(s);
        //2.String转int
        int iiii = Integer.parseInt(s);
        
        
        //String 和Integer的关系处理
        //1.String转Integer
        Integer iiiii = Integer.valueOf(s);
        System.out.println(iiiii);
        
        //2.Integer转String
        String ss = iiiii.toString();
    }

}