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Learn more about: _strtoi64, _wcstoi64, _strtoi64_l, _wcstoi64_l |
_strtoi64, _wcstoi64, _strtoi64_l, _wcstoi64_l |
05/18/2022 |
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ea2abc50-7bfe-420e-a46b-703c3153593a |
Convert a string to an __int64
value.
__int64 _strtoi64(
const char *strSource,
char **endptr,
int base
);
__int64 _wcstoi64(
const wchar_t *strSource,
wchar_t **endptr,
int base
);
__int64 _strtoi64_l(
const char *strSource,
char **endptr,
int base,
_locale_t locale
);
__int64 _wcstoi64_l(
const wchar_t *strSource,
wchar_t **endptr,
int base,
_locale_t locale
);
strSource
Null-terminated string to convert.
endptr
Pointer to character that stops scan.
base
Number base to use.
locale
The locale to use.
_strtoi64
returns the value represented in the string strSource
, except when the representation would cause an overflow, in which case it returns _I64_MAX
or _I64_MIN
. The function will return 0 if no conversion can be performed. _wcstoi64
returns values analogously to _strtoi64
.
_I64_MAX
and _I64_MIN
are defined in LIMITS.H.
If strSource
is NULL
or the base
is nonzero and either less than 2 or greater than 36, errno
is set to EINVAL
.
For more information about return codes, see errno
, _doserrno
, _sys_errlist
, and _sys_nerr
.
The _strtoi64
function converts strSource
to an __int64
. Both functions stop reading the string strSource
at the first character they can't recognize as part of a number. It may be the terminating null character, or it may be the first numeric character greater than or equal to base
. _wcstoi64
is a wide-character version of _strtoi64
; its strSource
argument is a wide-character string. These functions behave identically otherwise.
By default, this function's global state is scoped to the application. To change it, see Global state in the CRT.
TCHAR.H routine |
_UNICODE and _MBCS not defined |
_MBCS defined |
_UNICODE defined |
---|---|---|---|
_tcstoi64 |
_strtoi64 |
_strtoi64 |
_wcstoi64 |
_tcstoi64_l |
_strtoi64_l |
_strtoi64_l |
_wcstoi64_l |
The locale's LC_NUMERIC
category setting determines recognition of the radix character in strSource
; for more information, see setlocale
. The functions without the _l
suffix use the current locale; _strtoi64_l
and _wcstoi64_l
are identical to the corresponding function without the _l
suffix except that they use the locale passed in instead. For more information, see Locale.
If endptr
isn't NULL
, a pointer to the character that stopped the scan is stored at the location pointed to by endptr
. If no conversion can be performed (no valid digits were found or an invalid base was specified), the value of strSource
is stored at the location pointed to by endptr
.
_strtoi64
expects strSource
to point to a string of the following form:
[
whitespace
] [{+
|-
}] [0
[{x
|X
}]] [digits
|letters
]
A whitespace
may consist of space and tab characters, which are ignored. digits
are one or more decimal digits. letters
are one or more of the letters 'a' through 'z' (or 'A' through 'Z'). The first character that doesn't fit this form stops the scan. If base
is between 2 and 36, then it's used as the base of the number. If base
is 0, the initial characters of the string pointed to by strSource
are used to determine the base. If the first character is '0' and the second character isn't 'x' or 'X', the string is interpreted as an octal integer. If the first character is '0' and the second character is 'x' or 'X', the string is interpreted as a hexadecimal integer. If the first character is '1' through '9', the string is interpreted as a decimal integer. The letters 'a' through 'z' (or 'A' through 'Z') are assigned the values 10 through 35; only letters whose assigned values are less than base
are permitted. The first character outside the range of the base stops the scan. For example, if base
is 0 and the first character scanned is '0', an octal integer is assumed and an '8' or '9' character will stop the scan.
Function | Required header |
---|---|
_strtoi64 , _strtoi64_l |
<stdlib.h> |
_wcstoi64 , _wcstoi64_l |
<stdlib.h> or <wchar.h> |
For more compatibility information, see Compatibility.
Data conversion
Locale
localeconv
setlocale
, _wsetlocale
String to numeric value functions
strtod
, _strtod_l
, wcstod
, _wcstod_l
strtoul
, _strtoul_l
, wcstoul
, _wcstoul_l
atof
, _atof_l
, _wtof
, _wtof_l