How to sort an array by similarity in relation to an inputted word.

问题

I have on PHP array, for example:

$arr = array("hello", "try", "hel", "hey hello");

Now I want to do rearrange of the array which will be based on the most nearly close words between the array and my $search var.

How can I do that?

回答1:

This could be a quick solution by using http://php.net/manual/en/function.similar-text.php:

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.

$userInput = 'Bradley123';

$list = array('Bob', 'Brad', 'Britney');

usort($list, function ($a, $b) use ($userInput) {
    similar_text($userInput, $a, $percentA);
    similar_text($userInput, $b, $percentB);

    return $percentA === $percentB ? 0 : ($percentA > $percentB ? -1 : 1);
});

var_dump($list); //output: array("Brad", "Britney", "Bob");

Or by using http://php.net/manual/en/function.levenshtein.php:

The Levenshtein distance is defined as the minimal number of characters you have to replace, insert or delete to transform str1 into str2. The complexity of the algorithm is O(m*n), where n and m are the length of str1 and str2 (rather good when compared to similar_text(), which is O(max(n,m)**3), but still expensive).

$userInput = 'Bradley123';

$list = array('Bob', 'Brad', 'Britney');

usort($list, function ($a, $b) use ($userInput) {
    $levA = levenshtein($userInput, $a);
    $levB = levenshtein($userInput, $b);

    return $levA === $levB ? 0 : ($levA > $levB ? 1 : -1);
});

var_dump($list); //output: array("Britney", "Brad", "Bob");

回答2:

You can use levenshtein function

<?php
// input misspelled word
$input = 'helllo';

// array of words to check against
$words  = array('hello' 'try', 'hel', 'hey hello');

// no shortest distance found, yet
$shortest = -1;

// loop through words to find the closest
foreach ($words as $word) {

    // calculate the distance between the input word,
    // and the current word
    $lev = levenshtein($input, $word);

    // check for an exact match
    if ($lev == 0) {

        // closest word is this one (exact match)
        $closest = $word;
        $shortest = 0;

        // break out of the loop; we've found an exact match
        break;
    }

    // if this distance is less than the next found shortest
    // distance, OR if a next shortest word has not yet been found
    if ($lev <= $shortest || $shortest < 0) {
        // set the closest match, and shortest distance
        $closest  = $word;
        $shortest = $lev;
    }
}

echo "Input word: $input\n";
if ($shortest == 0) {
    echo "Exact match found: $closest\n";
} else {
    echo "Did you mean: $closest?\n";
}

?>

回答3:

if you want to sort your array, you can do this:

$arr = array("hello", "try", "hel", "hey hello");
$search = "hey"; //your search var

for($i=0; $i<count($arr); $i++) {
   $temp_arr[$i] = levenshtein($search, $arr[$i]);
}
asort($temp_arr);
foreach($temp_arr as $k => $v) {
    $sorted_arr[] = $arr[$k];
}

$sorted_arr should then be in descending order starting with the closest word to your search term.

回答4:

Another way is to use similar_text function which returns result in percents. See more http://www.php.net/manual/en/function.similar-text.php .

来源：https://stackoverflow.com/questions/7217746/how-to-sort-an-array-by-similarity-in-relation-to-an-inputted-word

标签

php

arrays

levenshtein-distance