PHP string segmentation and comparison _php techniques

Or use strcmp to judge, but this will tell you whether two strings are equal, but can't tell you where they are different.
My idea is to split a single string into letters (character) so that you can know exactly where the difference is.
Delimited string, use "Str_split" on it, syntax refer to "2". The result array is then output, and the advantage is that the space also acts as an element of the array. My previous example is because the previous string contains 2 spaces, and then one is only one. But the output is the same when you see the display.
You can also divide by other delimiters, such as "explode" or "preg_split", referring to "3" and "4". The former uses a simple split number, and the latter uses regular expressions. "Split" has been abolished (deprecated).
Another useful function is "str_word_count", which splits the string into arrays and clears both numbers and punctuation. If you want to count the frequency of words appearing, use "Array_count_values" and refer to "5".
Reference:
"1" http://us2.php.net/manual/en/language.operators.comparison.php
"2" Http://us2.php.net/manual/en/function.str-split.php1
"3" http://us2.php.net/manual/en/function.explode.php
"4" http://us2.php.net/manual/en/function.str-split.php
"5" http://us2.php.net/manual/en/function.array-count-values.php