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Data Conversion

These routines convert data from one form to another. Generally these routines execute faster than conversions you might write. Each routine that begins with a to prefix is implemented as a function and as a macro. See Choosing Between Functions and Macros for information about choosing an implementation.

Data-Conversion Routines

Routine Use
abs Find absolute value of integer
atof Convert string to float
atoi, _atoi64 Convert string to int
atol Convert string to long
_ecvt Convert double to string of specified length
_fcvt Convert double to string with specified number of digits following decimal point
_gcvt Convert double number to string; store string in buffer
_itoa, _i64toa, _itow, _i64tow Convert int to string
labs Find absolute value of long integer
_ltoa, _ltow Convert long to string
_mbbtombc Convert 1-byte multibyte character to corresponding 2-byte multibyte character
_mbcjistojms Convert Japan Industry Standard (JIS) character to Japan Microsoft (JMS) character
_mbcjmstojis Convert JMS character to JIS character
_mbctohira Convert multibyte character to 1-byte hiragana code
_mbctokata Convert multibyte character to 1-byte katakana code
_mbctombb Convert 2-byte multibyte character to corresponding 1-byte multibyte character
mbstowcs Convert sequence of multibyte characters to corresponding sequence of wide characters
mbtowc Convert multibyte character to corresponding wide character
strtod, wcstod Convert string to double
strtol, wcstol Convert string to long integer
strtoul, wcstoul Convert string to unsigned long integer
strxfrm, wcsxfrm Transform string into collated form based on locale-specific information
__toascii Convert character to ASCII code
tolower, towlower, _mbctolower Test character and convert to lowercase if currently uppercase
_tolower Convert character to lowercase unconditionally
toupper, towupper, _mbctoupper Test character and convert to uppercase if currently lowercase
_toupper Convert character to uppercase unconditionally
_ultoa, _ultow Convert unsigned long to string
wcstombs Convert sequence of wide characters to corresponding sequence of multibyte characters
wctomb Convert wide character to corresponding multibyte character
_wtof Convert wide-character string to a double
_wtoi, _wtoi64 Convert wide-character string to int or __int64
_wtol Convert wide-character string to long

See Also

Run-Time Routines by Category | Run-Time Routines and .NET Framework Equivalents