The
strspn() function returns the length of the initial substring of the string pointed to by
str1 that is made up of only those character contained in the string pointed to by
str2.
Syntax :
size_t strspn(const char *str1, const char *str2)
str1 : string to be scanned.
str2 : string containing the
characters to match.
Return Value : This function
returns the number of characters
in the initial segment of str1
which consist only of characters
from str2.
Output:
Length of initial segment matching 4
