PHP levenshtein() Function

PHP levenshtein() Function

❮ PHP String Reference


Calculate the Levenshtein distance between two strings:

echo levenshtein("Hello World","ello World");
echo "<br>";
echo levenshtein("Hello World","ello World",10,20,30);
Run example »

Definition and Usage

The levenshtein() function returns the Levenshtein distance between two strings.

The Levenshtein distance is the number of characters you have to replace, insert or delete to transform string1 into string2.

By default, PHP gives each operation (replace, insert, and delete) equal weight. However, you can define the cost of each operation by setting the optional insert, replace, and delete parameters.

Note: The levenshtein() function is not case-sensitive.

Note: The levenshtein() function is faster than the similar_text() function. However, similar_text() will give you a more accurate result with less modifications needed.



Parameter Description
string1 Required. First string to compare
string2 Required. Second string to compare
insert Optional. The cost of inserting a character. Default is 1
replace Optional. The cost of replacing a character. Default is 1
delete Optional. The cost of deleting a character. Default is 1

Technical Details

Return Value: Returns the Levenshtein distance between the two argument strings or -1, if one of the strings exceeds 255 characters
PHP Version: 4.0.1+

❮ PHP String Reference