How to output in golang

Go is a powerful programming language with an efficient, concise coding style and excellent concurrent programming capabilities. In golang, outputting information to the console is a common operation. This article will introduce you to golang's output functions and output formatting rules, as well as some common output methods.

1. Golang output function

In golang, there are two main functions that output information to the console:

1. fmt.Print()

The Print() function can directly output the passed parameters to the standard output stream (i.e. console). Use the output of this function, each parameter will be separated by spaces, ending with the last parameter. For example:

fmt.Print("Hello", "World")

The output result is:

Hello World

2. fmt.Println()

Println() function is similar to Print() function, but different The Println() function automatically adds a newline character between all passed arguments. For example:

fmt.Println("Hello", "World")

The output result is:

Hello World

2. Golang output formatting rules

The formatting rules in golang are controlled by using the percent sign % and some characters output format. The specific rules are as follows:

1. %v: can be output as a placeholder for any value.

fmt.Printf("%v\n", "Hello, World")

The output result is:

Hello, World

2. %d: used to output decimal integers.

fmt.Printf("%d\n", 123)

The output result is:

123

3. %f: used to output floating point numbers.

fmt.Printf("%f\n", 3.1415)

The output result is:

3.141500

4. %s: used to output string.

fmt.Printf("%s\n", "Hello, World")

The output result is:

Hello, World

5. %t: used to output Boolean values.

fmt.Printf("%t\n", true)

The output result is:

true

6. %p: used to output pointer address.

a := 123
fmt.Printf("%p\n", &a)

The output result is:

0xc0000120c8

7. %#v (# represents the printing type): Go syntax representation for output values.

a := 123
fmt.Printf("%#v\n", a)

The output result is:

123

3. Common output methods in golang

In addition to the above functions and rules, there are some common output methods in golang . Here is a brief introduction to several common methods:

1. log package

log package is the log output package provided by the golang standard library. Log information can be output to the console or file.

import "log"

func main() {
    log.Println("Hello, World")    // 输出到控制台
}

2. os package

The Stdout variable in the os package can be used to output information to the console. For example:

import "os"

func main() {
    os.Stdout.WriteString("Hello, World\n")
}

3. fmt.Sprintf()

The Sprintf() function is similar to the Printf() function. The difference is that the Sprintf() function will format the The string is returned as the return value instead of being output to the console. For example:

s := fmt.Sprintf("%s, %s", "Hello", "World")
fmt.Println(s)

The output result is:

Hello, World

4. bufio package

The bufio package provides some functions for efficient input/output operations. Including operations such as reading input, outputting to the console, and outputting to a file. For example:

import "bufio"
import "os"

func main() {
    writer := bufio.NewWriter(os.Stdout)
    writer.WriteString("Hello, World\n")
    writer.Flush()
}

The above are common output methods in golang. Readers can choose flexibly according to specific scenarios.

Summary

This article mainly introduces the output functions, output formatting rules and common output methods in golang. A solid foundation and skilled technology are the keys to writing good code. I hope the introduction in this article can help readers better understand and master golang's output operations.

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