[PDF] atof, atoi, _atoi64, atol - DbGroup UNIMORE Home Page

PDF document for free

1. PDF document for free

23689_6LibrerieC.pdf

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 _wtoi Convert wide-character string to int _wtol Convert wide-character string to long

Send feedback to MSDN. Look here for MSDN Online resources. atof, atoi, _atoi64, atol Convert strings to double (atof), integer (atoi, _atoi64), or long (atol). double atof( const char *string ); int atoi( const char *string ); __int64 _atoi64( const char *string ); long atol( const char *string );

Routine Required Header Compatibility atof and ANSI, Win 95, Win NT atoi ANSI, Win 95, Win NT _atoi64 Win 95, Win NT atol ANSI, Win 95, Win NT

For additional compatibility information, see Compatibility in the Introduction.

Libraries

LIBC.LIB Single thread static library, retail version LIBCMT.LIB Multithread static library, retail version MSVCRT.LIB Import library for MSVCRT.DLL, retail version

Return Value

Each function returns the double, int, __int64 or long value produced by interpreting the input characters as a number. The return value is 0 (for atoi and _atoi64), 0L (for atol), or

0.0 (for atof) if the input cannot be converted to a value of that type. The return value is

undefined in case of overflow.

Parameter

string

String to be converted

Remarks

These functions convert a character string to a double-precision floating-point value (atof), an integer value (atoi and _atoi64), or a long integer value (atol). 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 in the current locale. For more information on the LC_NUMERIC category, see setlocale. The longest string size that atof can handle is 100 characters. 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 ('\0') terminating the string. The string argument to atof has the following form: [whitespace] [sign] [digits] [.digits] [ {d | D | e | E }[sign]digits] A whitespace consists of space and/or tab characters, which are ignored; sign is either plus (+) or minus ( - ); and digits are one or more decimal digits. If no digits appear before the decimal point, at least one must appear after the decimal point. The decimal digits may be followed by an exponent, which consists of an introductory letter ( d, D, e, or E) and an optionally signed decimal integer. atoi, _atoi64, and atol do not recognize decimal points or exponents. The string argument for these functions has the form: [whitespace] [sign]digits where whitespace, sign, and digits are exactly as described above for atof.

Generic-Text Routine Mappings

TCHAR.H

Routine _UNICODE & _MBCS

Not Defined _MBCS Defined _UNICODE Defined _ttoi atoi atoi _wtoi _ttol atol atol _wtol

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 #include 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 | Floating-Point Support Routines | Locale Routines See Also _ecvt, _fcvt, _gcvt, setlocale, strtod, wcstol, strtoul Send feedback to MSDN. Look here for MSDN Online resources. strchr, wcschr, _mbschr

Find a character in a string.

char *strchr( const char *string, int c ); wchar_t *wcschr( const wchar_t *string, wint_t c ); unsigned char *_mbschr( const unsigned char *string, unsigned int c );

Routine Required Header Compatibility strchr ANSI, Win 95, Win NT wcschr or ANSI, Win 95, Win NT _mbschr Win 95, Win NT

For additional compatibility information, see Compatibility in the Introduction.

Libraries

LIBC.LIB Single thread static library, retail version LIBCMT.LIB Multithread static library, retail version MSVCRT.LIB Import library for MSVCRT.DLL, retail version

Return Value

Each of these functions returns a pointer to the first occurrence of c in string, or NULL if c is not found.

Parameters

string

Null-terminated source string

c

Character to be located

Remarks

The strchr function finds the first occurrence of c in string, or it returns NULL if c is not found. The null-terminating character is included in the search. wcschr and _mbschr are wide-character and multibyte-character versions of strchr. The arguments and return value of wcschr are wide-character strings; those of _mbschr are multibyte-character strings. _mbschr recognizes multibyte-character sequences according to the multibyte code page currently in use. These three functions behave identically otherwise.

Generic-Text Routine Mappings

TCHAR.H

Routine _UNICODE & _MBCS

Not Defined _MBCS Defined _UNICODE Defined _tcschr strchr _mbschr wcschr

Example

/* STRCHR.C: This program illustrates searching for a character * with strchr (search forward) or strrchr (search backward). */ #include #include int ch = 'r'; char string[] = "The quick brown dog jumps over the lazy fox"; char fmt1[] = " 1 2 3 4 5"; char fmt2[] = "12345678901234567890123456789012345678901234567890"; void main( void ) { char *pdest; int result; printf( "String to be searched: \n\t\t%s\n", string ); printf( "\t\t%s\n\t\t%s\n\n", fmt1, fmt2 ); printf( "Search char:\t%c\n", ch ); /* Search forward. */ pdest = strchr( string, ch ); result = pdest - string + 1; if( pdest != NULL ) printf( "Result:\tfirst %c found at position %d\n\n", ch, result ); else printf( "Result:\t%c not found\n" ); /* Search backward. */ pdest = strrchr( string, ch ); result = pdest - string + 1; if( pdest != NULL ) printf( "Result:\tlast %c found at position %d\n\n", ch, result ); else printf( "Result:\t%c not found\n" ); }

Output

String to be searched:

The quick brown dog jumps over the lazy fox 1 2 3 4 5 12345678901234567890123456789012345678901234567890

Search char: r

Result: first r found at position 12

Result: last r found at position 30

String Manipulation Routines

See Also strcspn, strncat, strncmp, strncpy, _strnicmp, strpbrk, strrchr, strstr Send feedback to MSDN. Look here for MSDN Online resources.

Decimals Documents PDF, PPT , Doc

[PDF] 3 decimals whose sum is 0.08

1. Math

2. Basic Math

3. Decimals

[PDF] 4 decimals whose sum is 2.35

[PDF] about decimals and percentages

[PDF] about decimals in maths

[PDF] add decimals practice problems

[PDF] add decimals within 1

[PDF] adding decimals across the whole

[PDF] adding decimals below 1

[PDF] adding decimals pdf

[PDF] adding decimals practice problems

12345 Next 200000 acticles

Politique de confidentialité -Privacy policy