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求教！怎样将整型转换成字符型并输出还是那个数字？？在线等待高手指教。

楼主harryho（基路亚）2003-02-01 20:11:22 在 C/C++ / C语言提问

怎样将整型转换成字符型并输出还是那个数字？？问题点数：20、回复次数：18Top

1 楼harryho（基路亚）回复于 2003-02-01 20:13:03 得分 0

怎样将整型转换成字符型并输出还是那个数字？？是用TC++编译的.Top

2 楼red_free（酒肉穿肠过，脂肪腰间留）回复于 2003-02-01 20:14:29 得分 0

printf("%c",a+30);假设a是一个1位的整形变量.Top

3 楼micropentium6（小笨|曾经的美好）回复于 2003-02-01 20:20:01 得分 5

char *_ecvt( double value, int count, int *dec, int *sign );

Converts a double number to a string

#include <stdlib.h>
#include <stdio.h>

void main( void )
{
int decimal, sign;
char *buffer;
int precision = 10;
double source = 3.1415926535;

buffer = _ecvt( source, precision, &decimal, &sign );
printf( "source: %2.10f buffer: '%s' decimal: %d sign: %d\n",
source, buffer, decimal, sign );
}

Output

source: 3.1415926535 buffer: '3141592654' decimal: 1 sign: 0

char *_fcvt( double value, int count, int *dec, int *sign );

Converts a floating-point number to a string

#include <stdlib.h>
#include <stdio.h>

void main( void )
{
int decimal, sign;
char *buffer;
double source = 3.1415926535;

buffer = _fcvt( source, 7, &decimal, &sign );
printf( "source: %2.10f buffer: '%s' decimal: %d sign: %d\n",
source, buffer, decimal, sign );
}

Output

source: 3.1415926535 buffer: '31415927' decimal: 1 sign: 0

Top

4 楼micropentium6（小笨|曾经的美好）回复于 2003-02-01 20:21:04 得分 0

#include <cstdlib>Top

5 楼harryho（基路亚）回复于 2003-02-01 20:22:52 得分 0

还是不行啊，显示是其它字符来的。
我是这样测试的。void main(){
int a=30;
printf("%c",a+30);
}
显示是一个大于号.Top

6 楼danmao（愤怒的小mao）回复于 2003-02-01 20:29:14 得分 6

#include <stdlib.h>
#include <stdio.h>

void main( void )
{
int decimal, sign;
char *buffer;
int precision = 10;
double source = 3.1415926535;

buffer = _ecvt( source, precision, &decimal, &sign );
printf( "source: %2.10f buffer: '%s' decimal: %d sign: %d\n",
source, buffer, decimal, sign );
}

char *_ecvt(
double value,
int count,
int *dec,
int *sign
);
Parameters
value
Number to be converted.
count
Number of digits stored.
dec
Stored decimal-point position.
sign
Sign of converted number.

还有很多，你自己查查。
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7 楼harryho（基路亚）回复于 2003-02-01 20:30:08 得分 0

在ecvt中，其中第二，三，四个参数是什么意思？？可以说得详细点吗？Top

8 楼harryho（基路亚）回复于 2003-02-01 20:31:31 得分 0

thank you.Top

9 楼micropentium6（小笨|曾经的美好）回复于 2003-02-01 20:34:27 得分 0

去查msdn：）Top

10 楼harryho（基路亚）回复于 2003-02-01 20:46:54 得分 0

边度有MSDN下载啊？？我部机无啊。Top

11 楼micropentium6（小笨|曾经的美好）回复于 2003-02-01 21:03:13 得分 0

我把它贴上来：）Top

12 楼micropentium6（小笨|曾经的美好）回复于 2003-02-01 21:06:34 得分 5

_ecvt
Converts a double number to a string.

char *_ecvt( double value, int count, int *dec, int *sign );

Function Required Header Compatibility
_ecvt <stdlib.h> Win 95, Win NT

For additional compatibility information, see Compatibility in the Introduction.

Libraries

LIBC.LIB Single thread static library, retail version
LIBCMT.LIB Multithread static library, retail version
MSVCRT.LIB Import library for MSVCRT.DLL, retail version

Return Value

_ecvt returns a pointer to the string of digits. There is no error return.

Parameters

value

Number to be converted

count

Number of digits stored

dec

Stored decimal-point position

sign

Sign of converted number

Remarks

The _ecvt function converts a floating-point number to a character string. The value parameter is the floating-point number to be converted. This function stores up to count digits of value as a string and appends a null character ('\0'). If the number of digits in value exceeds count, the low-order digit is rounded. If there are fewer than count digits, the string is padded with zeros.

Only digits are stored in the string. The position of the decimal point and the sign of value can be obtained from dec and sign after the call. The dec parameter points to an integer value giving the position of the decimal point with respect to the beginning of the string. A 0 or negative integer value indicates that the decimal point lies to the left of the first digit. The sign parameter points to an integer that indicates the sign of the converted number. If the integer value is 0, the number is positive. Otherwise, the number is negative.

_ecvt and _fcvt use a single statically allocated buffer for the conversion. Each call to one of these routines destroys the result of the previous call.
/////////////////////////////////////////////////////////////////

_fcvt
Converts a floating-point number to a string.

char *_fcvt( double value, int count, int *dec, int *sign );

Function Required Header Compatibility
_fcvt <stdlib.h> Win 95, Win NT

For additional compatibility information, see Compatibility in the Introduction.

Libraries

LIBC.LIB Single thread static library, retail version
LIBCMT.LIB Multithread static library, retail version
MSVCRT.LIB Import library for MSVCRT.DLL, retail version

Return Value

_fcvt returns a pointer to the string of digits. There is no error return.

Parameters

value

Number to be converted

count

Number of digits after decimal point

dec

Pointer to stored decimal-point position

sign

Pointer to stored sign indicator

Remarks

The _fcvt function converts a floating-point number to a null-terminated character string. The value parameter is the floating-point number to be converted. _fcvt stores the digits of value as a string and appends a null character ('\0'). The count parameter specifies the number of digits to be stored after the decimal point. Excess digits are rounded off to count places. If there are fewer than count digits of precision, the string is padded with zeros.

Only digits are stored in the string. The position of the decimal point and the sign of value can be obtained from dec and sign after the call. The dec parameter points to an integer value; this integer value gives the position of the decimal point with respect to the beginning of the string. A zero or negative integer value indicates that the decimal point lies to the left of the first digit. The parameter sign points to an integer indicating the sign of value. The integer is set to 0 if value is positive and is set to a nonzero number if value is negative.

_ecvt and _fcvt use a single statically allocated buffer for the conversion. Each call to one of these routines destroys the results of the previous call.

Top

13 楼Frank001（Frank）回复于 2003-02-01 21:22:33 得分 4

可以用下面的方法试试看：
#include <iostream>
using namespace std;

void main()
{
int a_i;
char num[10];
cin>>a_i; //输入整形数
itoa(a_i, num, 10);
cout<<num<<endl;
}Top

14 楼Frank001（Frank）回复于 2003-02-01 21:26:45 得分 0

itoa(a_i,num,10) //a_i为要转换的整形数，num转换后的字符串数组，10表示为10进制数的转换。Top

15 楼harryho（基路亚）回复于 2003-02-01 22:16:58 得分 0

实在太谢谢你们了，令我这个刚开始对C++有兴趣的人，真正找到了C++的乐趣。祝你们新年愉快。Top

16 楼Frank001（Frank）回复于 2003-02-02 15:33:53 得分 0

呵呵，希望对你有帮助，结贴吧。

新年快乐！Top

17 楼Caoyu015（酷鱼一代）回复于 2003-02-02 16:15:17 得分 0

《C的陷阱和缺陷》中有一段很精彩的程序。Top

18 楼fastzch（红领巾）回复于 2003-02-02 16:22:18 得分 0

这么一个简单的问题搞得大家这么大费周折，真是不可思议！
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