A complete guide to using Go language built-in packages!

2023.10.14

A complete guide to using Go language built-in packages!


Go language has many commonly used packages built-in, and rational use can greatly improve development efficiency. This article provides a brief overview of some of them, hoping to help you better use the built-in packages of the Go language.

Introduction to commonly used built-in packages in Go language

I. Overview

The Go language has built-in packages with many commonly used functions, which can be directly used for project development. Proficiency in built-in packages can greatly improve the efficiency of Go language programming.

This article will briefly introduce some commonly used built-in packages in the Go language, including

  • fmt package: formatting and printing
  • os package: platform related functions
  • io package: input and output operations
  • bufio package: cached IO
  • net/http package: HTTP network communication
  • encoding package: data encoding and decoding
  • flag package: command line parameter parsing
  • reflect package: reflection mechanism
  • sort package: sorting functions
  • testing package: testing framework

2. fmt package

The fmt package implements formatted IO related functions:

  • Print series functions print output
  • Scan series function format input
  • Sprintf formatted string concatenation
  • Errorf error creation

3. os package

The os package provides platform-dependent functions:

  • File operations: open, delete, rename files
  • Directory operations: create and delete directories
  • Environment variables: getting and setting environment variables
  • Process/command operations: start processes, etc.

Cross-platform code can be written using the os package.

4. io package

The io package provides basic IO primitives:

  • Reader/Writer interface
  • Pipe pipe communication
  • EOF end flag
  • LimitedReader reads according to restrictions

The io package defines an abstract interface for all IO operations.

5. bufio package

bufio implements buffered IO operations:

  • Buffering reading and writing improves efficiency
  • Read, Write series methods
  • Custom buffer read and write objects
  • Expandable buffering

Suitable for IO operation optimization.

6. net/http package

The net/http package provides HTTP client and server implementations:

  • Client sends request
  • Server handles the request
  • Transport underlying transport
  • response/request object
  • timeout mechanism

Many web services are built on the net/http package.

7. encoding package

encoding implements various data encoding and decoding:

  • JSON encoding and decoding
  • XML encoding and decoding
  • Base64 encoding and decoding

The encoding package can be used in daily encoding conversion scenarios. 

8. flag package

The flag package implements command line parameter parsing:

  • Define command line flag parameters
  • Parse command line input parameters
  • Commonly used flag types (bool, int, etc.)
  • Custom flag type

Many CLI tools use the flag package.

9. reflect package

reflect implements the reflection mechanism:

  • TypeOf reflection type information
  • ValueOf reflection value information
  • Setting variables via reflection
  • Reflection calling method

Reflection is an important capability of dynamic languages.

10. sort package

The sort package implements various data sorting:

  • Sort slices of built-in types
  • Sort custom types
  • Sort by multiple conditions
  • Stability ranking

Just implement a few interfaces to sort.

11. Testing package

testing provides testing functions:

  • Add test case
  • Run tests and generate reports
  • coverage calculation
  • benchmark stress test
  • mock data

Can write unit tests etc.

Summarize

Go language has many commonly used packages built-in, and rational use can greatly improve development efficiency. This article provides a brief overview of some of them, hoping to help you better use the built-in packages of the Go language.