How to replace first and last 3 characters of a st

问题:

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Closed 2 years ago.

I want to replace the first 3 characters and last 3 characters with * sign without using any built in functions.

$string = array("johndoee","shawnmarsh","peterparker","johndoee","shawnmarsh","peterparker");

Can you guide me? Is there any way to do this?

回答1:

This seems fairly pointless, but it's possible using string access and modification by character.

foreach ($strings as &$string) {
    for ($i=0; $i < 3; $i++) {
        $string[$i] = '*';
        $string[-($i+1)] = '*';
    }
}

Note that this won't work properly if the string contains multibyte characters, because it's accessing the string as a byte array.

Also note that this requires PHP 7.1 in order to use the negative indexes. If you don't have PHP 7.1 I don't know of a way to replace the last three characters without using any functions.