golang installation library fmt

Golang is a programming language developed by Google, referred to as Go. It has the characteristics of efficiency, reliability, and simplicity. It can be used to quickly develop high-performance web applications or server programs. When writing Golang programs, libraries are an indispensable part. These libraries allow us to easily complete development tasks and improve development efficiency. Among them, the fmt library is one of the most commonly used libraries in the Golang language. It provides some basic input and output functions, such as formatted output, printing strings, etc. This article will introduce how to install and use the fmt library in Golang.

1. Golang environment configuration

Before installing the Golang library, we need to configure the Golang environment first. The specific steps are as follows:

1. Download the Golang installation package: We can download the Golang installation package from the official website at https://golang.org/dl/. Just choose the installation package that suits your operating system.

2. Install Golang: After the download is complete, double-click the installation package to complete the installation.

3. Set environment variables: In order for the operating system to find the installation path of Golang, we need to add the installation path to the environment variable. The specific steps are: Open Computer Properties -> Advanced System Settings -> Environment Variables.

2. Install the fmt library

After installing Golang, we can start installing the fmt library. The fmt library in the Golang program comes by default, so we do not need to perform additional installation operations. We only need to use it according to the following methods.

1. Import the fmt library: Before using the fmt library in a Golang program, we need to import the library first. The specific method is to add the following statement in the code:

import "fmt"

2. Use the fmt library: After importing the fmt library, we can use the library in the code. For example, the following code can use the Printf function in the fmt library to output "Hello, world!":

package main

import "fmt"

func main() {
    fmt.Printf("Hello, world!")
}

In the above code, the Printf function is used to format the output. The first parameter is the output format. The second parameter is the content to be output.

3. Use the fmt library

After importing and installing the fmt library, we can use it to complete our development tasks. Here are some common methods of the fmt library:

1.Printf

The Printf function is used to format output and can be used to output strings, numbers, Boolean values, etc.

The following is a sample code that uses the Printf function to output a string and an integer:

package main

import "fmt"

func main() {
    str := "hello"
    num := 123
    fmt.Printf("%s, world! This is a number: %d", str, num)
}

Execute the code and the output result is:

hello, world! This is a number: 123

In the above code , %s and %d represent the strings and numbers that need to be output, which correspond to the two parameters in the Printf function. \n and its effect is to output a newline character.

2.Println

The Println function is used to output a line of characters, and can be used to output strings, numbers, Boolean values, etc. Below is a sample code that uses the Println function to output a string and an integer:

package main

import "fmt"

func main() {
    str := "hello"
    num := 123
    fmt.Println(str, "world! This is a number:", num)
}

Executing the code, the output is:

hello world! This is a number: 123

In the above code, the Println function accepts multiple parameters, they are separated by spaces, and the final output result will be automatically wrapped.

3.Sprintf

The Sprintf function is used to format a string into a new string and can be used to output strings, numbers, Boolean values, etc. Below is a sample code that uses the Sprintf function to output a string and an integer:

package main

import "fmt"

func main() {
    str := "hello"
    num := 123
    result := fmt.Sprintf("%s, world! This is a number: %d", str, num)
    fmt.Println(result)
}

Executing the code, the output is:

hello, world! This is a number: 123

In the above code, the Sprintf function is the same as Printf The function is similar except that it returns the formatted result in a string.

4. Summary

In Golang development, the fmt library is a very important library. It provides settings and control of multiple output formats, allowing us to easily output various contents. . Installing and using the fmt library is also very simple. You only need to import the library and call the corresponding function in the code to complete the task.

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