Read and write files with the os package, work with io.Reader and io.Writer, and use bufio for line reading and fast output.

• Reading And Writing Files
• io.Reader And io.Writer
• Buffered IO With bufio

Encode Go structs to JSON with struct tags and omitempty, and decode JSON safely with Unmarshal, NewDecoder and unknown field checks.

• Encoding JSON And Struct Tags
• Decoding JSON

Build HTTP servers with net/http routing and timeouts, and call APIs with clients that time out, close bodies and check status codes.

• Writing An HTTP Server
• Making HTTP Requests

Format and parse dates with Go's reference time, handle durations, timezones and the monotonic clock, and work with strings, strconv and strings.Builder.

• Formatting And Parsing Time
• Durations, Timezones And Monotonic Time
• strings, strconv And strings.Builder