PHP Function to Remove all Double and Triple Spaces from a String

An often overlooked tweak when cleaning a user or system input string is to make sure that there aren’t any double, triple or basically multiple instances of a space character next to one another, possibly caused by string concatenation or just a sticky spacebar key.

Below is a handy little function which works in a recursive manner to ensure that our input string only contains single instances of the space character:

function compressMultiSpacesToSingleSpace($inputstring) {
    if (!(strpos($inputstring, '  ') === false)) {
        $inputstring = str_replace('  ', ' ', $inputstring);
        $inputstring = compressMultiSpacesToSingleSpace($inputstring);
    }
    return $inputstring;
}

Simple in design, but it gets the job done.

(Of course, it might have been even easier to achieve this through some nifty regex one could argue…)