Golang commonly used standard library introduction and examples
Golang (also known as Go) is a programming language that uses concise syntax and efficient performance. As an open source language, its standard library provides many useful features that can save us time and effort during the development process. In this article, we will introduce some commonly used Golang standard libraries and provide corresponding sample code.
1. fmt standard library
fmt standard library provides formatting operations for input and output. It contains various methods, such as Println, Printf, and Sprintf, for printing to standard output or a string.
Sample code:
package main import "fmt" func main() { name := "World" fmt.Println("Hello", name) fmt.Printf("The value of pi is %f ", 3.1415) result := fmt.Sprintf("The square of 5 is %d", 5*5) fmt.Println(result) }
2. os standard library
The os standard library provides the function of interacting with the operating system. It contains many methods, such as operating files, environment variables and command line parameters.
Sample code:
package main import ( "fmt" "os" ) func main() { file, err := os.Open("test.txt") if err != nil { fmt.Println("File can't be opened:", err) return } defer file.Close() stat, err := file.Stat() if err != nil { fmt.Println("File can't be read:", err) return } fmt.Println("File size:", stat.Size()) }
3. net/http standard library
The net/http standard library provides the implementation of HTTP client and server. It allows us to create HTTP requests, listen on ports, and handle HTTP requests.
Sample code:
package main import ( "fmt" "net/http" ) func main() { http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) { fmt.Fprint(w, "Hello World") }) http.ListenAndServe(":8080", nil) }
4. encoding/json standard library
encoding/json standard library is used for encoding and decoding JSON. It provides methods such as Marshal and Unmarshal, making it very convenient to operate JSON data in Golang.
Sample code:
package main import ( "encoding/json" "fmt" ) type Person struct { Name string `json:"name"` Age int `json:"age"` } func main() { jsonStr := `{"name":"John", "age":30}` var p Person if err := json.Unmarshal([]byte(jsonStr), &p); err != nil { fmt.Println("JSON parsing error:", err) return } fmt.Println(p.Name, p.Age) p.Age = 31 data, err := json.Marshal(p) if err != nil { fmt.Println("JSON encoding error:", err) return } fmt.Println(string(data)) }
The above is only a small part of the Golang standard library. In fact, there are many other powerful functions that can be achieved through the standard library. By learning and using these standard libraries, we can write Golang programs more efficiently and implement various functions quickly. If you are interested in Golang, I encourage you to continue to dig into these standard libraries and try to use them. I wish you success in your learning and development!
The above is the detailed content of Usage and examples of common Golang standard libraries. For more information, please follow other related articles on the PHP Chinese website!