| Localization library | |||||||||||||||||||||||||
| Regular expressions library(C++11) | |||||||||||||||||||||||||
| Formatting library(C++20) | |||||||||||||||||||||||||
| Null-terminated sequence utilities | |||||||||||||||||||||||||
| Byte strings | |||||||||||||||||||||||||
| Multibyte strings | |||||||||||||||||||||||||
| Wide strings | |||||||||||||||||||||||||
| Primitive numeric conversions | |||||||||||||||||||||||||
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| Text encoding identifications | |||||||||||||||||||||||||
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| Functions | ||||||||||||||||||||||||||||||||||||
| Character classification | ||||||||||||||||||||||||||||||||||||
| Character manipulation | ||||||||||||||||||||||||||||||||||||
| Conversions to numeric formats | ||||||||||||||||||||||||||||||||||||
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| String manipulation | ||||||||||||||||||||||||||||||||||||
| String examination | ||||||||||||||||||||||||||||||||||||
| Character array functions | ||||||||||||||||||||||||||||||||||||
| Miscellaneous | ||||||||||||||||||||||||||||||||||||
Defined in header <cinttypes> | ||
std::intmax_t strtoimax(constchar* nptr,char** endptr,int base); | (1) | (since C++11) |
std::uintmax_t strtoumax(constchar* nptr,char** endptr,int base); | (2) | (since C++11) |
Interprets an integer value in a byte string pointed to bynptr.
Discards any whitespace characters (as identified by callingstd::isspace) until the first non-whitespace character is found, then takes as many characters as possible to form a validbase-n (where n=base) integer number representation and converts them to an integer value. The valid integer value consists of the following parts:
0) indicating octal base (applies only when the base is8 or0)0x or0X) indicating hexadecimal base (applies only when the base is16 or0)The set of valid values for base is{0, 2, 3, ..., 36}. The set of valid digits for base-2 integers is{0, 1}, for base-3 integers is{0, 1, 2}, and so on. For bases larger than10, valid digits include alphabetic characters, starting fromAa for base-11 integer, toZz for base-36 integer. The case of the characters is ignored.
Additional numeric formats may be accepted by the currently installed Clocale.
If the value ofbase is0, the numeric base is auto-detected: if the prefix is0, the base is octal, if the prefix is0x or0X, the base is hexadecimal, otherwise the base is decimal.
If the minus sign was part of the input sequence, the numeric value calculated from the sequence of digits is negated as if byunary minus in the result type.
The functions sets the pointer pointed to byendptr to point to the character past the last character interpreted. Ifendptr is a null pointer, it is ignored.
If thenptr is empty or does not have the expected form, no conversion is performed, and (ifenptr is not a null pointer) the value ofnptr is stored in the object pointed to byendptr.
Contents |
| nptr | - | pointer to the null-terminated byte string to be interpreted |
| endptr | - | pointer to a pointer to character. |
| base | - | base of the interpreted integer value |
#include <cinttypes>#include <iostream>#include <string> int main(){std::string str="helloworld";std::intmax_t val= std::strtoimax(str.c_str(), nullptr,36);std::cout<< str<<" in base 36 is "<< val<<" in base 10\n"; char* nptr; val= std::strtoimax(str.c_str(),&nptr,30);if(nptr!=&str[0]+ str.size())std::cout<< str<<" in base 30 is invalid."<<" The first invalid digit is '"<<*nptr<<"'\n";}
Output:
helloworld in base 36 is 1767707668033969 in base 10helloworld in base 30 is invalid. The first invalid digit is 'w'
(C++11)(C++11)(C++11) | converts a string to a signed integer (function)[edit] |
(C++11)(C++11) | converts a string to an unsigned integer (function)[edit] |
(C++11) | converts a byte string to an integer value (function)[edit] |
(C++11) | converts a byte string to an unsigned integer value (function)[edit] |
(C++11)(C++11) | converts a wide string tostd::intmax_t orstd::uintmax_t (function)[edit] |
| converts a byte string to a floating-point value (function)[edit] | |
(C++17) | converts a character sequence to an integer or floating-point value (function)[edit] |
(C++11) | converts a byte string to an integer value (function)[edit] |
C documentation forstrtoimax,strtoumax | |
