PHP string replace match whole word

multiple word in string replaced by this

    $String = 'Team Members are committed to delivering quality service for all buyers and sellers.';
    echo $String;
    echo "<br>";
    $String = preg_replace(array('/\bTeam\b/','/\bfor\b/','/\ball\b/'),array('Our','to','both'),$String);
    echo $String;
    Result: Our Members are committed to delivering quality service to both buyers and sellers.

You want to use regular expressions. The \b matches a word boundary.

$text = preg_replace('/\bHello\b/', 'NEW', $text);

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If $text contains UTF-8 text, you'll have to add the Unicode modifier "u", so that non-latin characters are not misinterpreted as word boundaries:

$text = preg_replace('/\bHello\b/u', 'NEW', $text);