Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/Statistical.php
public static function COUNTA(...$args)
    {
        $returnValue = 0;

        // Loop through arguments
        $aArgs = Functions::flattenArray($args);
        foreach ($aArgs as $arg) {
            // Is it a numeric, boolean or string value?
            if ((is_numeric($arg)) || (is_bool($arg)) || ((is_string($arg) && ($arg != '')))) {
                ++$returnValue;
            }
        }

        return $returnValue;
    }
public static function COUNTA(...$args)
    {
        $returnValue = 0;

        // Loop through arguments
        $aArgs = Functions::flattenArray($args);
        foreach ($aArgs as $arg) {
            // Is it a numeric, boolean or string value?
            if ((is_numeric($arg)) || (is_bool($arg)) || ((is_string($arg) && ($arg != '')))) {
                ++$returnValue;
            }
        }

        return $returnValue;
    }
COUNTA.

Counts the number of cells that are not empty within the list of arguments

Excel Function:
COUNTA(value1[,value2[, ...]])

@category Statistical Functions

@param mixed ...$args Data values

@return int