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similar_text

(PHP 4, PHP 5, PHP 7, PHP 8)

similar_text — Calculate the similarity between two strings

Опис

similar_text(string $string1, string $string2, float &$percent = null): int

This calculates the similarity between two strings as described in Programming Classics: Implementing the World's Best Algorithms by Oliver (ISBN 0-131-00413-1). Note that this implementation does not use a stack as in Oliver's pseudo code, but recursive calls which may or may not speed up the whole process. Note also that the complexity of this algorithm is O(N**3) where N is the length of the longest string.

Параметри

string1

The first string.

string2

The second string.

Зауваження:

Swapping the string1 and string2 may yield a different result; see the example below.

percent

By passing a reference as third argument, similar_text() will calculate the similarity in percent, by dividing the result of similar_text() by the average of the lengths of the given strings times 100.

Значення, що повертаються

Returns the number of matching chars in both strings.

The number of matching characters is calculated by finding the longest first common substring, and then doing this for the prefixes and the suffixes, recursively. The lengths of all found common substrings are added.

Приклади

Приклад #1 similar_text() argument swapping example

This example shows that swapping the string1 and string2 argument may yield different results.

<?php
$sim = similar_text('bafoobar', 'barfoo', $perc);
echo "similarity: $sim ($perc %)\n";
$sim = similar_text('barfoo', 'bafoobar', $perc);
echo "similarity: $sim ($perc %)\n";

Поданий вище приклад виведе щось схоже на:

similarity: 5 (71.428571428571 %)
similarity: 3 (42.857142857143 %)

Прогляньте також