itoa

char *  itoa ( int value, char * str, int base );

Converts an integer value to a null-terminated string using the specified base and stores the result in the array given by str parameter.

If base is 10 and value is negative, the resulting string is preceded with a minus sign (-). With any other base, valueis always considered unsigned.

str should be an array long enough to contain any possible value: (sizeof(int)*8+1) for radix=2, i.e. 17 bytes in 16-bits platforms and 33 in 32-bits platforms.

Parameters

value

Value to be converted to a string.

str

Array in memory where to store the resulting null-terminated string.

base

Numerical base used to represent the value as a string, between 2 and 36, where 10 means decimal base, 16 hexadecimal, 8 octal, and 2 binary.

Return Value

A pointer to the resulting null-terminated string, same as parameter str.

Portability

This function is not defined in ANSI-C and is not part of C++, but is supported by some compilers.

A standard-compliant alternative for some cases may be sprintf:

• sprintf(str,"%d",value) converts to decimal base.
• sprintf(str,"%x",value) converts to hexadecimal base.
• sprintf(str,"%o",value) converts to octal base.

Example

/* itoa example */

#include <stdio.h>

#include <stdlib.h>

int main ()

{

  int i;

  char buffer [33];

  printf ("Enter a number: ");

  scanf ("%d",&i);

  itoa (i,buffer,10);

  printf ("decimal: %s\n",buffer);

  itoa (i,buffer,16);

  printf ("hexadecimal: %s\n",buffer);

  itoa (i,buffer,2);

  printf ("binary: %s\n",buffer);

  return 0;

}

Output:

Enter a number: 1750

decimal: 1750

hexadecimal: 6d6

binary: 11011010110