List some important methods in Golang

The Go language (or Golang for short) is an open source high-level programming language developed by Google. It combines the features of languages ​​such as C and Python and is regarded as a fast, efficient, scalable and easy-to-learn programming language. This article will list some important methods in Golang to help beginners better understand its features and functions.

1. fmt method

The fmt package of Go language provides many functions and methods related to input and output. Among them, the Println method allows us to output text to the console (usually used for debugging and process logging).

fmt.Println("Hello, world!")

Output:

Hello, world!

2. strconv method

Golang’s strconv package provides many functions and methods related to string conversion. Among them, the Itoa method can convert integer variables into string types.

import "strconv"

sum := 123
str := strconv.Itoa(sum)
fmt.Println("The sum is " str)

Output:

The sum is 123

3. time method

Golang’s time package provides functions and methods related to date and time. Among them, the Now method can return the current local time.

import "time"

now := time.Now()

fmt.Println("The current time is " now.Format("2006-01-02 15:04:05"))

Output:

The current time is 2021-05-12 16:04:28

4. net/http method

Golang’s net/http package provides functions and methods related to the HTTP protocol. Among them, the Get method can send an HTTP GET request to the specified server to obtain the response content.

import "net/http"
import "fmt"

resp, err := http.Get("http://www.google.com")
if err != nil {

fmt.Println("An error occurred", err)

} else {

fmt.Println(resp.StatusCode)

}

Output:

200

5. os method

Golang’s os package provides many operating system-related functions and methods. Among them, the Chdir method can modify the current directory.

import "os"
import "fmt"

os.Chdir("/tmp")
pwd, err := os.Getwd()
if err != nil {

fmt.Println("An error occurred", err)

} else {

fmt.Println("The current directory is", pwd)

}

Output:

The current directory is /tmp

6. math method

Golang’s math package provides mathematical functions and methods. Among them, the Sqrt method can calculate the positive square root of a value.

import "math"
import "fmt"

n := 16.0
fmt.Println("The square root of 16 is", math.Sqrt(n))

Output:

The square root of 16 is 4

7. io/ioutil method

Golang’s io/ioutil package provides Functions and methods related to file and directory I/O. Among them, the ReadFile method can read the contents of the specified file as a byte array.

import "io/ioutil"
import "fmt"

data, err := ioutil.ReadFile("/etc/hosts")
if err != nil {

fmt.Println("An error occurred", err)

} else {

fmt.Println("The file contains", len(data), "bytes")

}

Output:

The file contains 415 bytes

8. sync method

Golang’s sync package provides functions and methods related to concurrency and synchronization. Among them, the WaitGroup method can control the synchronization of multiple goroutines and wait for all goroutines to be executed before returning the result.

import "sync"

var wg sync.WaitGroup

wg.Add(3)

go func() {

fmt.Println("This is goroutine 1")
wg.Done()

}()

go func() {

fmt.Println("This is goroutine 2")
wg.Done()

}()

go func() {

fmt.Println("This is goroutine 3")
wg.Done()

}()

wg.Wait()

Output:

This is goroutine 1
This is goroutine 2
This is goroutine 3

Summary:

Golang enumerated methods cover some methods in Golang’s core package, briefly introducing their basic usage and functions. With in-depth research on Golang, developers can better utilize these methods to make programs more efficient, more reliable, and easier to maintain.

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