output_file.json

{"cards": [
    {
        "cardType": "MasterCard",
        "cardNumber": "5567894523129089"
    },
    {
        "cardType": "Invalid: more than 19 digits",
        "cardNumber": "59012345678901234567890"
    },
    {
        "cardType": "Visa",
        "cardNumber": "4123456789123"
    },
    {
        "cardType": "AmericanExpress",
        "cardNumber": "347856341908126"
    },
    {
        "cardType": "Discover",
        "cardNumber": "6011111100007756"
    },
    {
        "cardType": "Invalid: not a possible card number",
        "cardNumber": "3601112345678789"
    },
    {
        "cardType": "MasterCard",
        "cardNumber": "5167894523129089"
    },
    {
        "cardType": "Visa",
        "cardNumber": "4123456789123999"
    },
    {
        "cardType": "AmericanExpress",
        "cardNumber": "377856341908126"
    },
    {
        "cardType": "MasterCard",
        "cardNumber": "5367894523129089"
    },
    {
        "cardType": "Invalid: non numeric characters",
        "cardNumber": "6011*890HJrt6789"
    },
    {
        "cardType": "Invalid: empty/null card number",
        "cardNumber": null
    }
]}