The strspn () function in C

Function size_t strspn (const char * str1, const char * str2) calculates the length of the first character segment of the str1 string containing the characters in str2

Declaring the function strspn () in C

Here is the declaration for strspn () in C:

 size_t strspn ( const char * str1 , const char * str2 ) 

Parameters

str1 - Chain to be scanned.

str2 - String containing characters to match in str1.

Returns the value

This function returns the number of characters in the string segment of the original str1 string, but only the characters in str2.

For example

The following C program illustrates the usage of strspn () in C:

 #include #include int main () { int len ; const char str1 [] = "ABCDEFG019874" ; const char str2 [] = "ABCD" ; len = strspn ( str1 , str2 ); printf ( "Do dai cua chuoi ket noi dau tien la = %dn" , len ); return ( 0 ); } 

Compiling and running the above C program will result:

The strspn () function in C Picture 1

According to Tutorialspoint

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