Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Cell/Coordinate.php
public static function buildRange(array $pRange)
    {
        // Verify range
        if (empty($pRange) || !is_array($pRange[0])) {
            throw new Exception('Range does not contain any information');
        }

        // Build range
        $imploded = [];
        $counter = count($pRange);
        for ($i = 0; $i < $counter; ++$i) {
            $pRange[$i] = implode(':', $pRange[$i]);
        }
        $imploded = implode(',', $pRange);

        return $imploded;
    }
public static function buildRange(array $pRange)
    {
        // Verify range
        if (empty($pRange) || !is_array($pRange[0])) {
            throw new Exception('Range does not contain any information');
        }

        // Build range
        $imploded = [];
        $counter = count($pRange);
        for ($i = 0; $i < $counter; ++$i) {
            $pRange[$i] = implode(':', $pRange[$i]);
        }
        $imploded = implode(',', $pRange);

        return $imploded;
    }
Build range from coordinate strings.

@param array $pRange Array containg one or more arrays containing one or two coordinate strings

@throws Exception

@return string String representation of $pRange