std::memchr

 

C++

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Technical Specifications

 

Strings library

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Null-terminated byte strings

Functions
Character manipulation
isalnum isalpha islower isupper isdigit isxdigit isblank (C++11)	iscntrl isgraph isspace isprint ispunct tolower toupper
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atof atoiatolatoll strtolstrtoll	strtoulstrtoull strtofstrtodstrtold strtoimaxstrtouimax (C++11)(C++11)
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strlen strcmp strncmp strcoll strchr strrchr	strspn strcspn strpbrk strstr strtok
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memchr
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strerror

 

Defined in header <cstring>
const void* memchr( const void* ptr, int ch, std::size_t count );
void* memchr(       void* ptr, int ch, std::size_t count );

Converts ch to unsigned char and locates the first occurrence of that value in the initial count characters (each interpreted as unsigned char) of the object pointed to by ptr.

Parameters

ptr	-	pointer to the object to be examined
ch	-	character to search for
count	-	number of characters to examine

Return value

Pointer to the location of the character, or NULL if no such character is found.

Example

Search an array of characters.

Run this code

#include <iostream>
#include <cstring>
 
int main()
{
    char arr[] = {'a','\0','a','A','a','a','A','a'};
    char *pc = (char*)std::memchr(arr,'A',sizeof arr);
    if (pc != NULL)
       std::cout << "search character found\n";
    else
       std::cout << "search character not found\n";
}

Output:

search character found

See also

strchr	finds the first occurrence of a character (function)
findfind_iffind_if_not (C++11)	finds the first element satisfying specific criteria (function template)
C documentation for memchr