Fancy Barcodes JS Fundamentals

function fancyBarcodes(array) {
    let codesNumber = array.shift();
    let regex = /@#+(?<barcode>[A-Z][a-zA-Z0-9]{4,}[A-Z])@#/;

    for (let i = 0; i < codesNumber; i++) {
        let string = regex.exec(array[i]);

        if (string !== null) {
            let valid = string.groups.barcode;

            let productGroup = ``;
            for (let currSymbol of valid) {

                if (isNaN(currSymbol) === false) {
                    productGroup += currSymbol;
                }
            }
            if (productGroup == ``) {
                productGroup = `00`;
            }
            console.log(`Product group: ${productGroup}`);
        } else {
            console.log("Invalid barcode");
        }
    }
}