_wtoi, _wtoi64, _wtol

Converts a wide-character string to an integer (_wtoi and _wtoi64) or to a long integer (_wtol).

int _wtoi( const wchar_t *string );

__int64 _wtoi64( wchar_t *string );

long _wtol( const wchar_t *string );

For additional compatibility information, see Compatibility in the Introduction.

Libraries

Return Value

Each function returns the int, __int64, or long value produced by interpreting the input characters as a number. If the input cannot be converted to a value of the appropriate type, _wtoi and _wtoi64 return 0 and _wtol returns 0L. The return value is undefined in case of overflow.

Parameter

string

String to be converted

Remarks

The _wtoi and _wtoi64 function converts a wide-character string to an integer value. _wtol converts a wide-character string to a long integer value. The input string is a sequence of characters that can be interpreted as a numerical value of the specified type. The output value is affected by the setting of the LC_NUMERIC category of the current locale. (For more information on the LC_NUMERIC category, see setlocale.The function stops reading the input string at the first character that it cannot recognize as part of a number. This character may be the null character (L'\0') terminating the string.

The string argument for these functions has the form

[whitespace] [sign]digits

A whitespace consists of space and/or tab characters, which are ignored. sign is either plus (+) or minus ( – ). digits is one or more decimal digits. _wtoi, _wtoi64, and _wtol do not recognize decimal points or exponents.

Example

/* ATOF.C: This program shows how numbers stored
 * as strings can be converted to numeric values
 * using the atof, atoi, and atol functions.
 */

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

void main( void )
{
   char *s; double x; int i; long l;

   s = "  -2309.12E-15";    /* Test of atof */
   x = atof( s );
   printf( "atof test: ASCII string: %s\tfloat:  %e\n", s, x );

   s = "7.8912654773d210";  /* Test of atof */
   x = atof( s );
   printf( "atof test: ASCII string: %s\tfloat:  %e\n", s, x );

   s = "  -9885 pigs";      /* Test of atoi */
   i = atoi( s );
   printf( "atoi test: ASCII string: %s\t\tinteger: %d\n", s, i );

   s = "98854 dollars";     /* Test of atol */
   l = atol( s );
   printf( "atol test: ASCII string: %s\t\tlong: %ld\n", s, l );
}

Output

atof test: ASCII string:   -2309.12E-15   float:  -2.309120e-012
atof test: ASCII string: 7.8912654773d210   float:  7.891265e+210
atoi test: ASCII string:   -9885 pigs      integer: -9885
atol test: ASCII string: 98854 dollars      long: 98854

Data Conversion Routines |  Locale Routines

See Also   atoi, _ecvt, _fcvt, _gcvt