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

Introduction to Commonly Used Built-in Packages in Go Language

1. Overview

Go language has many built-in packages with common functions, which can be directly used for project development. Mastering the 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-specific functions
• io package: input and output operations
• bufio package: Buffered IO
• net/http package: HTTP network communication
• encoding package: data encoding and decoding
• flag package: command line argument parsing
• reflect package: reflection mechanism
• sort package: sorting functionality
• testing package: testing framework

2. fmt package

The fmt package implements the following functions for formatting IO:

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

3. os package

The os package provides platform-dependent functionality:

• File operations: open, delete, rename files
• Directory operations: create and delete directories
• Environment variables: Get and set environment variables
• Process/command operation: start process, etc.

The os package allows you to write cross-platform code.

4. io package

The io package provides basic IO primitives:

• Reader/Writer Interface
• Pipe communication
• EOF End mark
• LimitedReader reads by limit

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

5. bufio package

bufio implements buffered IO operations:

• Buffered reading and writing improves efficiency
• Read, Write series of methods
• Custom buffered read and write objects
• Expandable buffer

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 argument parsing:

• Define command line flag parameters
• Parsing command line input parameters
• Common flag types (bool, int, etc.)
• Custom flag type

Many CLI tools use the flag package.

9. reflect package

reflect implements the reflection mechanism:

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

Reflection is an important capability of dynamic languages.

10. sort package

The sort package implements various data sorting methods:

• Sorting slices of built-in types
• Sorting custom types
• Multiple condition sorting
• Stability ranking

Just implement a few interfaces to sort.

11. Testing Package

testing provides testing functionality:

• Adding a test case
• Run tests and generate reports
• Coverage calculation
• Benchmark
• Mock Data

Can write unit tests etc.

Summarize

Go language has many commonly used packages built in, and proper use can greatly improve development efficiency. This article briefly summarizes some of them, hoping to help everyone better use the built-in packages of Go language.