wcsspn

Header: <wchar.h>

Returns the length of the maximum initial segment of the wide string pointed to by dest, that consists of only the characters found in wide string pointed to by src.

# Declarations

size_t wcsspn( const wchar_t* dest, const wchar_t* src );

(since C95)

# Parameters

• dest: pointer to the null-terminated wide string to be analyzed
• src: pointer to the null-terminated wide string that contains the characters to search for

# Return value

The length of the maximum initial segment that contains only characters from wide string pointed to by src

# Example

#include <locale.h>
#include <wchar.h>
 
int main(void)
{
    wchar_t dest[] = L"白猫 黑狗 甲虫";
    const wchar_t src[] = L" 狗猫 白黑 ";
    const size_t len = wcsspn(dest, src);
    dest[len] = L'\0'; /* terminates the segment to print it out */
 
    setlocale(LC_ALL, "en_US.utf8");
    wprintf(L"The length of maximum initial segment is %td.\n"
            L"The segment is \"%ls\".\n", len, dest);
}

# See also

• wcscspn
• wcspbrk
• C++ documentation