Java每日解惑

package jinlai.ding.com.javajiehuo;

import java.math.BigDecimal;

public class IsOld {

    /**
     * 判断奇数（（计算一个数字是否奇数））
     * @param args
     */
    public static void main(String[] args) {
        //谜题1：奇数性
        System.out.println(isOld(-3));
        System.out.println(isOldYes(-3));
        //谜题2:找零时刻
        System.out.println(2.00 - 1.10);
        System.out.println((200 - 110) + "cents");
        System.out.println(new BigDecimal("2.00").subtract(new BigDecimal("1.10")));
        //谜题3：长整数
        System.out.println(longDivision());
        System.out.println(longDivisionL());
        //谜题4：初级问题
        System.out.println(12345 + 54321);
        System.out.println(12345 + 5432l);
        System.out.println(12345 + 5432L);
        //谜题5：十六进制的趣事
        System.out.println(Long.toHexString(0x100000000L + 0xcafebabe));
        System.out.println(Long.toHexString(0x100000000L + 0xcafebabeL));
        
    }

    /**
     * 错误的判断方法
     * @param i
     * @return
     */
    public static boolean isOld(int i){
        return i % 2 ==1;
    }
    
    /**
     * 正确的判断方法
     * @param i
     * @return
     */
    public static boolean isOldYes(int i){
        return (i & 1) != 0;
    }
    /**
     * 微妙除以毫秒 溢出计算
     * @return
     */
    public static long longDivision(){
        final long MICROS_PER_DAY = 24 * 60 * 60 * 1000 * 1000;
        final long MILLIS_PER_DAY = 24 * 60 * 60 * 1000;
        return MICROS_PER_DAY / MILLIS_PER_DAY;
    }
    /**
     * 微妙除以毫秒 不溢出计算
     * @return
     */
    public static long longDivisionL(){
        final long MICROS_PER_DAY = 24L * 60 * 60 * 1000 * 1000;
        final long MILLIS_PER_DAY = 24L * 60 * 60 * 1000;
        return MICROS_PER_DAY / MILLIS_PER_DAY;
    }
    
}