一、原型:
char *itoa( int value, char *string,int radix);
二、函數說明:
三、函數簡單實現:
#include <iostream>
#include <string>
using namespace std;
char* My_itoa(int value,char str[],int radix)
{
char temp[33];
char *tp = temp;
int i;
unsigned v;
int sign;
char *sp;
if(radix > 36 || radix < 1)
return 0;
sign = (radix == 10 && value < 0); //十進制負數
if(sign)
v = -value;
else
v = (unsigned)value;
while(v || tp == temp) //轉化操作
{
i = v % radix;
v = v / radix;
if(i < 10)
*tp++ = i + '0';
else
*tp++ = i + 'a' - 10;
}
if(str == 0)
str = (char*)malloc((tp - temp) + sign + 1);
sp = str;
if(sign) //是負數的話把負號先加入數組
*sp++ = '-';
while(tp > temp)
*sp++ = *--tp;
*sp = 0;
return str;
}
int main()
{
long int num;
int radix; //輸入的幾進製表示
char str[256];
cout<<"請輸入整數和進制數:";
cin>>num>>radix;
My_itoa(num,str,radix);
cout<<"整數轉換爲字符串後:";
cout<<str<<endl;
return 0;
}