Home Backend Development Golang The difference between golang constants and variables

The difference between golang constants and variables

Dec 03, 2019 am 11:53 AM
golang

The difference between golang constants and variables

Go language constants

Constant refers to a fixed value that the program may not change during its execution. These fixed values ​​are also called literals. ​ ​ ​ (Recommended learning: go)

A constant can be any basic data type like an integer constant, a floating point constant, a character constant or a string literal. There are also enumeration constants.

The constants are the same, except that their values ​​cannot be modified after being defined by yourself. Conventional variable processing.

Constant definition

With the const keyword, you can specify a friendly name for a literal constant:

const Pi float64 = 3.14159265358979323846
const zero = 0.0 // 无类型浮点常量
const (
size int64 = 1024
eof = -1 // 无类型整型常量
)
const u, v float32 = 0, 3 // u = 0.0, v = 3.0,常量的多重赋值
const a, b, c = 3, 4, "foo"
// a = 3, b = 4, c = "foo", 无类型整型和字符串常量
Copy after login

Go language variable

A variable is nothing but a name given to a storage area that our program can manipulate. Each variable in Go has a specific type, which determines the size and layout of the variable memory; can determine the range of values ​​stored within the memory; and group operations can be applied to the variable.

A variable name can consist of letters, numbers and underscores. It must start with a letter or underline. Uppercase and lowercase letters are different because Go is case-sensitive.

Initialization of variables

For scenarios that require initialization when declaring variables, the var keyword can be retained, but it is no longer a necessary element, as shown below:

var v1 int = 10 // 正确的使用方式1
var v2 = 10 // 正确的使用方式2,编译器可以自动推导出v2的类型
v3 := 10 // 正确的使用方式3,编译器可以自动推导出v3的类型
Copy after login

The above is the detailed content of The difference between golang constants and variables. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

How to safely read and write files using Golang? How to safely read and write files using Golang? Jun 06, 2024 pm 05:14 PM

Reading and writing files safely in Go is crucial. Guidelines include: Checking file permissions Closing files using defer Validating file paths Using context timeouts Following these guidelines ensures the security of your data and the robustness of your application.

How to configure connection pool for Golang database connection? How to configure connection pool for Golang database connection? Jun 06, 2024 am 11:21 AM

How to configure connection pooling for Go database connections? Use the DB type in the database/sql package to create a database connection; set MaxOpenConns to control the maximum number of concurrent connections; set MaxIdleConns to set the maximum number of idle connections; set ConnMaxLifetime to control the maximum life cycle of the connection.

Golang framework vs. Go framework: Comparison of internal architecture and external features Golang framework vs. Go framework: Comparison of internal architecture and external features Jun 06, 2024 pm 12:37 PM

The difference between the GoLang framework and the Go framework is reflected in the internal architecture and external features. The GoLang framework is based on the Go standard library and extends its functionality, while the Go framework consists of independent libraries to achieve specific purposes. The GoLang framework is more flexible and the Go framework is easier to use. The GoLang framework has a slight advantage in performance, and the Go framework is more scalable. Case: gin-gonic (Go framework) is used to build REST API, while Echo (GoLang framework) is used to build web applications.

How to save JSON data to database in Golang? How to save JSON data to database in Golang? Jun 06, 2024 am 11:24 AM

JSON data can be saved into a MySQL database by using the gjson library or the json.Unmarshal function. The gjson library provides convenience methods to parse JSON fields, and the json.Unmarshal function requires a target type pointer to unmarshal JSON data. Both methods require preparing SQL statements and performing insert operations to persist the data into the database.

How to find the first substring matched by a Golang regular expression? How to find the first substring matched by a Golang regular expression? Jun 06, 2024 am 10:51 AM

The FindStringSubmatch function finds the first substring matched by a regular expression: the function returns a slice containing the matching substring, with the first element being the entire matched string and subsequent elements being individual substrings. Code example: regexp.FindStringSubmatch(text,pattern) returns a slice of matching substrings. Practical case: It can be used to match the domain name in the email address, for example: email:="user@example.com", pattern:=@([^\s]+)$ to get the domain name match[1].

Transforming from front-end to back-end development, is it more promising to learn Java or Golang? Transforming from front-end to back-end development, is it more promising to learn Java or Golang? Apr 02, 2025 am 09:12 AM

Backend learning path: The exploration journey from front-end to back-end As a back-end beginner who transforms from front-end development, you already have the foundation of nodejs,...

How to use predefined time zone with Golang? How to use predefined time zone with Golang? Jun 06, 2024 pm 01:02 PM

Using predefined time zones in Go includes the following steps: Import the "time" package. Load a specific time zone through the LoadLocation function. Use the loaded time zone in operations such as creating Time objects, parsing time strings, and performing date and time conversions. Compare dates using different time zones to illustrate the application of the predefined time zone feature.

Golang framework development practical tutorial: FAQs Golang framework development practical tutorial: FAQs Jun 06, 2024 am 11:02 AM

Go framework development FAQ: Framework selection: Depends on application requirements and developer preferences, such as Gin (API), Echo (extensible), Beego (ORM), Iris (performance). Installation and use: Use the gomod command to install, import the framework and use it. Database interaction: Use ORM libraries, such as gorm, to establish database connections and operations. Authentication and authorization: Use session management and authentication middleware such as gin-contrib/sessions. Practical case: Use the Gin framework to build a simple blog API that provides POST, GET and other functions.

See all articles