Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Shared/StringHelper.php
public static function getCurrencyCode()
    {
        if (!empty(self::$currencyCode)) {
            return self::$currencyCode;
        }
        self::$currencyCode = '$';
        $localeconv = localeconv();
        if (!empty($localeconv['currency_symbol'])) {
            self::$currencyCode = $localeconv['currency_symbol'];

            return self::$currencyCode;
        }
        if (!empty($localeconv['int_curr_symbol'])) {
            self::$currencyCode = $localeconv['int_curr_symbol'];

            return self::$currencyCode;
        }

        return self::$currencyCode;
    }
public static function getCurrencyCode()
    {
        if (!empty(self::$currencyCode)) {
            return self::$currencyCode;
        }
        self::$currencyCode = '$';
        $localeconv = localeconv();
        if (!empty($localeconv['currency_symbol'])) {
            self::$currencyCode = $localeconv['currency_symbol'];

            return self::$currencyCode;
        }
        if (!empty($localeconv['int_curr_symbol'])) {
            self::$currencyCode = $localeconv['int_curr_symbol'];

            return self::$currencyCode;
        }

        return self::$currencyCode;
    }
Get the currency code. If it has not yet been set explicitly, try to obtain the
symbol information from locale.

@return string