std::strncmp
From cppreference.com
Defined in header <cstring>
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int strncmp(
const
char
* lhs, const
char
* rhs, std::size_t count )
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Compares at most count
The sign of the result is the sign of the difference between the values of the first pair of characters (both interpreted as unsigned char
The behavior is undefined when access occurs past the end of either array lhs or rhs. The behavior is undefined when either lhs or rhs
Parameters
| lhs, rhs | - | pointers to the possibly null-terminated arrays to compare |
| count | - | maximum number of characters to compare |
Return value
Negative value if lhs appears before rhs in lexicographical order.
Zero if lhs and rhs compare equal, or if count
Positive value if lhs appears after rhs in lexicographical order.
Notes
This function is not locale-sensitive, unlike std::strcoll and std::strxfrm
Example
Run this code
#include <cstring> #include <iostream> void demo(const char* lhs, const char* rhs, int sz) { const int rc = std::strncmp(lhs, rhs, sz); if (rc < 0) std::cout << "First " << sz << " chars of [" << lhs << "] precede [" << rhs << "]\n"; else if (rc > 0) std::cout << "First " << sz << " chars of [" << lhs << "] follow [" << rhs << "]\n"; else std::cout << "First " << sz << " chars of [" << lhs << "] equal [" << rhs << "]\n"; } int main() { demo("Hello, world!", "Hello, everybody!", 13); demo("Hello, everybody!", "Hello, world!", 13); demo("Hello, everybody!", "Hello, world!", 7); demo("Hello, everybody!" + 12, "Hello, somebody!" + 11, 5); }
Output:
First 13 chars of [Hello, world!] follow [Hello, everybody!] First 13 chars of [Hello, everybody!] precede [Hello, world!] First 7 chars of [Hello, everybody!] equal [Hello, world!] First 5 chars of [body!] equal [body!]
See also
| compares two strings (function) |
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| compares a certain amount of characters from two wide strings (function) |
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| compares two buffers (function) |
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| compares two strings in accordance to the current locale (function) |
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C documentation for strncmp
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