Question

I am developing a screening logic where complete text of content to be matched with list of keywords in php via regular expression.
I am using the following code which match words properly and make it bold.

$pattern = "/mango|apple|banana/";
$text = "i like banana and apple alot";
$replacement = "<strong>$0</strong>";
echo preg_replace($pattern, $replacement, $text);

this code properly match and make matched word enclosed in strong like

i like <strong>banana</strong> and <strong>apple</strong> alot.

But i want to replace banana as

b****a and apple as a****e 

instead of making it bold.

Can anyone help me how it will be possible.

Answer 1

You can try using preg_replace_callback instead of preg_replace.

preg_replace_callback($pattern, function($matches){
    $str = $matches[0];
    $len = strlen($str);
    $stars = str_repeat('*', $len-2);
    return $str[0].$stars.$str[$len-1];
}, $text);

Updated to create a dynamic number of stars