How it works...

Instead of simply scanning the input line by line and using strings.Split and other methods to parse the CSV format, Go offers a better way. The NewReader function in the encoding/csv package returns the Reader structure, which provides the API to read the CSV file. The Reader struct keeps variables to configure the read parameters, according to your needs.

The FieldsPerRecord parameter of Reader is a significant setting. This way the cell count per row could be validated. By default, when set to 0, it is set to the number of records in a first line. If a positive value is set, the number of records must match. If a negative value is set, there is no cell count validation.

Another interesting configuration is the Comment parameter, which allows you to define the comment characters in the parsed data. In the example, a whole line is ignored this way.

Go 1.10 now disallows the use of nonsensical comma and comment settings. This means null, carriage return, newline, invalid runes, and the Unicode replacement character. Also, setting comma and comment equal to each other is forbidden.
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