进制转换

package com.jiepu.jfinal;

/**
 * java进制转换
 *
 */
public class App 
{
    public static void main( String[] args )
    {
        System.out.println( "Hello World!" );
        
        int n1 = 14;
        //十进制转成十六进制：
        System.out.println(Integer.toHexString(n1));
        //十进制转成八进制
       System.out.println(Integer.toOctalString(n1));
        //十进制转成二进制
       System.out.println(Integer.toBinaryString(12));
        
        //十六进制转成十进制
       System.out.println(Integer.valueOf("FFFF",16).toString());
        //十六进制转成二进制
       System.out.println(Integer.toBinaryString(Integer.valueOf("FFFF",16)));
        //十六进制转成八进制
       System.out.println(Integer.toOctalString(Integer.valueOf("FFFF",16)));
        
       System.out.println("===");
        //八进制转成十进制
        System.out.println(Integer.valueOf("576",8).toString());
        //八进制转成二进制
       System.out.println(Integer.toBinaryString(Integer.valueOf("23",8)));
        //八进制转成十六进制
       System.out.println(Integer.toHexString(Integer.valueOf("23",8)));

    //二进制转十进制
        System.out.println(Integer.valueOf("10100",2).toString());
        //二进制转八进制
       System.out.println(Integer.toOctalString(Integer.parseInt("10100", 2)));
        //二进制转十六进制
       System.out.println(Integer.toHexString(Integer.parseInt("10100", 2)));
    }
}

//将字符串a， b， c,d分别采用10,2,16,8进制转换成数字
//------------------------------------------------
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#include <string>

int main()
{
	char a[] = "100";
	char b[] = "100";
	char c[] = "0x11";
	char d[] = "100";
	int x, y, z,m;
	x = strtol( a, NULL, 10 );
	y = strtol( b, NULL, 2 );
	z = strtol( c, NULL, 16 );
	m = strtol( d, NULL, 8 );
	printf( "x = %d\n", x );
	printf( "y = %d\n", y );
	printf( "z = %d\n", z );
	printf( "m = %d\n", m );
	getch();
	return 0;
}

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
//函数itob实际上是一个整数转任意进制(2~36)
void itob(int n, char s[], int b);

void new_reverse(char s[]);

int main(void)
{
	char buffer[10];
	int iTmp, radix, flag;

	while (1)
	{
		printf("Please input a int number(q to quit): ");
		flag = scanf("%d", &iTmp);
		if (flag != 1)
			break;
		printf("Please input the radix in dec num: ");
		scanf("%d", &radix);
		while (getchar() != '\n');
		itob(iTmp, buffer, radix);
		printf("Dec num %d in radix %d is %s\n\n", iTmp, radix, buffer);
	}

	system("pause");
	return 0;
}
//整型转字符型(含进制转化): 编写函数itob(n,s,b),将整数n转换为以b为底的数,结果存入s. 例如,itob(n,s,16)把整数n格式化成十六进制整数保存在s中.
void itob(int n, char s[], int b)
{
	static char digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	int i, sign;

	if (b < 2 || b > 36)
	{
		fprintf(stderr, "Can not suppoert base %d\n", b);
		exit (0);
	}

	if ((sign = n) < 0)
		n = -n;
	i = 0;
	do 
	{
		s[i++] = digits[n % b];
	} while ((n /= b) > 0);

	if (sign < 0)
		s[i++] = '-';
	s[i] = '\0';
	new_reverse(s);
}

void new_reverse(char s[])
{
	int c, i, j;

	for (i = 0, j = strlen(s)-1; i < j; i++,j--)
	{
		c = s[i];
		s[i] = s[j];
		s[j] = c;
	}
}