levenshtein
string$string1,
string$string2,
[int$insertion_cost = 1],
[int$replacement_cost = 1],
[int$deletion_cost = 1]
): int
The Levenshtein distance is defined as the minimal number of characters you have to replace, insert or delete to transform string1 into string2. The complexity of the algorithm is O(m*n), where n and m are the length of string1 and string2 (rather good when compared to similar_text, which is O(max(n,m)**3), but still expensive).
If insertion_cost, replacement_cost
and/or deletion_cost are unequal to 1,
the algorithm adapts to choose the cheapest transforms.
E.g. if $insertion_cost + $deletion_cost < $replacement_cost,
no replacements will be done, but rather inserts and deletions instead.
Parameters
- string1
-
One of the strings being evaluated for Levenshtein distance.
- string2
-
One of the strings being evaluated for Levenshtein distance.
- insertion_cost
-
Defines the cost of insertion.
- replacement_cost
-
Defines the cost of replacement.
- deletion_cost
-
Defines the cost of deletion.
Return Values
This function returns the Levenshtein-Distance between the two argument strings or -1, if one of the argument strings is longer than the limit of 255 characters.
Changelog
| Version | Description |
| 8.0.0 | Prior to this version, levenshtein had to be called with either two or five arguments. |