Replace word with stars (exact length)

Question

am trying to replace a word in a string BUT i want to get the word found in the function and replace it with a word with stars with the exact length ?

Is this possible or do i need to do this in some other way ?

$text = "Hello world, its 2018";
$words = ['world', 'its'];


echo str_replace($words, str_repeat("*", count(FOUND) ), $text);

Answer 1

You could use a regular expression to do that :

$text = preg_replace_callback('~(?:'.implode('|',$words).')~i', function($matches){
    return str_repeat('*', strlen($matches[0]));
}, $text);
echo $text ; // "Hello *****, *** 2018"

You also could secure this using preg_quote before to use preg_replace_callback() :

 $words = array_map('preg_quote', $words);

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EDIT : The following code is another way, that use a foreach() loop, but prevent unwanted behaviors (replacing part of words), and allows multi-bytes characters:

$words = ['foo', 'bar', 'bôz', 'notfound'];
$text = "Bar&foo; bAr notfoo, bôzo bôz :Bar! (foo), notFOO and NotBar or 'bar' foo";
$expt = "***&***; *** notfoo, bôzo *** :***! (***), notFOO and NotBar or '***' ***";

foreach ($words as $word) {
    $text = preg_replace_callback("~\b$word\b~i", function($matches) use ($word) {
        return str_ireplace($word, str_repeat('*', mb_strlen($word)), $matches[0]);
    }, $text);
}

echo $text, PHP_EOL, $expt ;