substr_compare Binary safe comparison of two strings from an offset, up to length characters &reftitle.description; intsubstr_compare stringmain_str stringstr intoffset intlength boolcase_insensitivity&false; substr_compare compares main_str from position offset with str up to length characters. &reftitle.parameters; main_str The main string being compared. str The secondary string being compared. offset The start position for the comparison. If negative, it starts counting from the end of the string. length The length of the comparison. The default value is the largest of the length of the str compared to the length of main_str minus the offset. case_insensitivity If case_insensitivity is &true;, comparison is case insensitive. &reftitle.returnvalues; Returns < 0 if main_str from position offset is less than str, > 0 if it is greater than str, and 0 if they are equal. If offset is equal to (prior to PHP 7.2.18, 7.3.5) or greater than the length of main_str, or the length is set and is less than 0, (or, prior to PHP 5.5.11, less than 1) substr_compare prints a warning and returns &false;. &reftitle.changelog; &Version; &Description; 7.2.18, 7.3.5 offset may now be equal to the length of main_str. 5.5.11 length may now be 0. 5.1.0 Added the possibility to use a negative offset. &reftitle.examples; ]]> &reftitle.seealso; strncmp