The C language finds the string and returns the index

The C language itself does not have a function to find a string and return an index, although it is easier to say that you can get an index by writing a lookup function.

C language has a strchr function to find the first position of the character, the key is this function, if used skillfully, you can also get the index of the found string

1     char *str_1 = "wtwq211"; 2     char *str_2 = STRCHR (str_1, ' Q '); 3     printf ("%s\n", str_2); 4 5     int index= Str_2-str_1;6     printf ("%c\n", Str_1[index]);       

The C language finds the string and returns the index