std::strtol, std::strtoll

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C++ Standard Library
Language Utilities library Strings library Containers library Algorithms library Iterators library Numerics library Input/output library Localizations library Regular expressions library (C++11) Atomic operations library (C++11) Thread support library (C++11)
Strings library
Narrow character strings Wide character strings Classes basic_string char_traits
Narrow null-terminated strings
Functions Character manipulation isalnum isalpha islower isupper isdigit isxdigit isblank (C++11) iscntrl isgraph isspace isprint ispunct tolower toupper Conversions to numeric formats atof atoi strtol strtoul strtof String manipulation strcpy strncpy strcat strncat strxfrm String examination strlen strcmp strncmp strcoll strchr strrchr strspn strcspn strpbrk strstr strtok Memory manipulation memchr memcmp memset memcpy memmove Miscellaneous strerror

Defined in header <cstdlib>
long      strtol( const char *str, char **str_end, int base );
long long strtoll( const char *str, char **str_end, int base );		(C++11 feature)

Interprets an integer value in a character string pointed to by str.

Function discards any whitespace characters until first non-whitespace character is found. Then it takes as many characters as possible to form a valid base-n (where n=base) integer number representation and converts them to an integer value. The valid integer value consists of the following parts:

• (optional) plus or minus sign
• (optional) prefix (0) indicating octal base (applies only when the base is 8)
• (optional) prefix (0x or 0X) indicating hexadecimal base (applies only when the base is 16)
• a sequence of digits

The set of valid digits for base-2 integer is 01, for base-3 integer is 012, and so on. For bases larger than 10, valid digits include alphabetic characters, starting from Aa for base-11 integer, to Zz for base-36 integer. The case of the characters is ignored.

The functions sets the pointer pointed to by str_end to point to the character past the last character interpreted. If str_end is NULL, it is ignored.

Contents 1 Parameters 2 Return value 3 Example 4 See also

[edit] Parameters

str	-	pointer to the null-terminated character string to be interpreted
str_end	-	pointer to a pointer to character.
base	-	base of the interpreted integer value

[edit] Return value

integer value corresponding to the contents of str on success. If the converted value falls out of range of corresponding return type, range error occurs and LONG_MAX, LONG_MIN, LLONG_MAX or LLONG_MIN is returned. If no conversion can be performed, ​0​ is returned.

This section is incomplete Reason: fix links to limits

[edit] Example

This section is incomplete

[edit] See also

atoi atol atoll	converts a character string to an integer value (function)
strtoul strtoull	converts a character string to an unsigned integer value (function)