strcmpi( ) function in C is same as strcmp() function. But, strcmpi( ) function is not case sensitive. i.e, “A” and “a” are treated as same characters. Where as, strcmp() function treats “A” and “a” as different characters. strcmpi() function is non standard function which may not available in standard library in C. Both functions compare two given strings and returns zero if they are same. If length of string1 < string2, it returns < 0 value. If length of string1 > string2, it returns > 0 value. Syntax for strcmp( ) function is given below. int strcmpi ( const char * str1, const char * str2 );