The Go language does not have static global variables. It uses a more flexible way to handle the need for global variables. Global variables are usually declared at the package level, that is, variables declared outside the function. These Global variables are visible throughout the package and can be used in any function in the package.

The operating environment of this article: Windows 10 system, go1.20 version, DELL G3 computer.

Go language does not have static global variables, it uses a more flexible way to handle the needs of global variables. In Go language, global variables are usually declared at the package level, that is, variables declared outside functions. These global variables are visible throughout the package and can be used in any function in the package.

However, the Go language emphasizes encapsulation and maintainability and discourages the use of global variables. Instead, the Go language encourages the use of local variables and function parameters to pass data. This approach is more conducive to code organization and testing, and can avoid concurrency problems that may arise from sharing data between multiple coroutines.

When we really need to use global state throughout the entire program, the Go language provides a very concise way to achieve it. You can define a variable at the package level and use it as a local variable in a package-level function. This way, the variable is initialized each time the function is called, but its state remains unchanged. Because the variable is restricted to the scope of the function, other functions cannot directly access it, thus achieving an effect similar to a static global variable.

The Go language does not have static variables, but similar effects are often needed in the actual process, such as configuration information, etc. The following writing method uses reading and writing username (username) as an example to achieve an effect similar to a static variable.

First look at the writing method of calling in main.go:

//在main函數(shù)中set好username的值，然后在其他函數(shù)中獲取username的值
//main函數(shù)中進行set操作
func?main()?{
config.WithConfig().SetConfig()
initApp()
}
//該方法進行get操作
func?initApp(){
config.WithConfig().GetConfig()
}

Next, let’s look at the writing method of config.go:

package?config
//配置結構體
type?Config?struct?{
username?string
}
//關鍵在此，聲明一個全局變量所有的讀寫操作實際上都是在操作c
var?c?*Config
func?init()?{
c?=?new(Config)
}
//方便鏈式操作
func?WithConfig()?*Config?{
return?c.WithConfig()
}
func?(c?*Config)?WithConfig()?*Config?{
return?c
}
//寫
func?(c?*Config)?SetConfig(name?string)?{
c.username?=?name
}
//讀
func?(c?*Config)?GetConfig()?string?{
return?c.username
}

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