PHP Functions Essential Reference

levenshtein

int levenshtein (string string_one, string string_two, 
 [int insert_cost], [int substitution_cost], 
 [int delete_cost]) 

string_one	First string to compare
string_two	Second string to compare
insert_cost	Cost of inserting a character
substitution_cost	Cost of substituting a character
delete_cost	Cost of deleting a character

Calculates the Levenshtein distance between two strings.

Returns:

Integer greater than zero (0); on error, an integer less than 0

Description:

levenshtein() is used to find the Levenshtein distance between two strings. The Levenshtein distance is defined as the fewest number of insert, substitution, and delete operations needed to transform one string into another string. The function is not case-sensitive. ...