java，包装类

package org.hanqi.array;

public class BaoZhuang {

    public static void main(String[] args) {

        //包装类
        Long l=new Long(100);
        Long l1=new Long("1000");

        String str=1000+"";//数值转成字符串
        long l2=l1.longValue();//字符串转成数值，从包装类转成基本数据类型

        System.out.println("12="+l2);
        long l3=Long.parseLong("1200");//静态方法从字符串转成long型
        //int
        Integer i=new Integer("100");
        Integer.parseInt("100");
        //float
        Float f=new Float("123.45");
        Float.parseFloat("123.45");
        //double
        Double d=new Double("12345.67");
        Double.parseDouble("123.78");
        //boolean
        Boolean b=new Boolean("aaaa");
        System.out.println(b.booleanValue());
    }

}