private static function cleanUp(string $number) : string
    {
        $firstChar = $number[0];

        if ($firstChar === '+' || $firstChar === '-') {
            $number = \substr($number, 1);
        }

        $number = \ltrim($number, '0');

        if ($number === '') {
            return '0';
        }

        if ($firstChar === '-') {
            return '-' . $number;
        }

        return $number;
    }
private static function cleanUp(string $number) : string
    {
        $firstChar = $number[0];

        if ($firstChar === '+' || $firstChar === '-') {
            $number = \substr($number, 1);
        }

        $number = \ltrim($number, '0');

        if ($number === '') {
            return '0';
        }

        if ($firstChar === '-') {
            return '-' . $number;
        }

        return $number;
    }
private static function cleanUp ( string $ number ) : string { $ firstChar = $ number [ 0 ] ; if ( $ firstChar === '+' || $ firstChar === '-' ) { $ number = \ substr ( $ number , 1 ) ; } $ number = \ ltrim ( $ number , '0' ) ; if ( $ number === '' ) { return '0' ; } if ( $ firstChar === '-' ) { return '-' . $ number ; } return $ number ; }
Removes optional leading zeros and + sign from the given number.

@param string $number The number, validated as a non-empty string of digits with optional sign.

@return string
Removes optional leading zeros and + sign from the given number .