从句子中匹配1个单词

how can i search for 1 or 2 word match?

<?php
$a = key1, key2, key3;
$b = key3, key4, key5;

if (strpos($a,$b) != false) {
    echo 'Great Is Found';
}
?>

this "strpos" returns result only if all sentence it's the same, what if I want even only 1 or 2 words match?

Try with array_intersect, array_map and explode

$a = "key1, key2, key3";
$b = "key3, key4, key5";

$intersect = array_intersect(array_map('trim',explode(",",$a)), array_map('trim',explode(",",$b)));

if ($intersect) {
    echo 'Great Is Found';
    var_dump($intersect);
}

After quick read it seems that you are looking for similar_text or levenshtein methods.