How to use golang variables

Golang is a high-performance programming language with a concise syntax that is easy to learn and use. In Golang, variables are an essential element in the program. This article will introduce how to use variables in Golang.

1. Definition of variables

In Golang, the definition format of variables is var variable name data type. For example:

var num int
var name string

Among them, num is a variable of type int, and name is a variable of type string. It should be noted that Golang is a statically typed language, and variables must specify the data type when they are defined.

2. Assignment of variables

After the variable is defined, you can assign a value to the variable through an assignment statement. For example:

num = 10
name = "golang"

You can also assign an initial value to the variable while defining it. For example:

var num int = 10
var name string = "golang"

You can also use short declarations to define variables. For example:

num := 10
name := "golang"

A short declaration uses the := operator to define and initialize variables, and the data type of the variable can be automatically deduced. It should be noted that short declarations can only be used inside functions and cannot be used outside functions.

3. Scope of variables

The scope of a variable refers to the visible range of the variable in the program. In Golang, the scope of variables can be divided into global variables and local variables.

Global variables are defined outside the function and can be used by all functions in the program. For example:

var num int = 10

func main() {
    fmt.Println(num)
}

Local variables are defined inside the function and can only be used inside the function. For example:

func main() {
    var num int = 10
    fmt.Println(num)
}

It should be noted that in Golang, the case of the first letter of a variable name determines the scope of the variable. Variables starting with an uppercase letter are global variables, and variables starting with a lowercase letter are local variables. .

4. Definition of constants

Unlike variables, the value of a constant cannot be changed during the running of the program. In Golang, constants are defined using the const keyword. For example:

const num int = 10
const name string = "golang"

It should be noted that constants cannot be defined using := assignment syntax, and the data type must be explicitly specified.

5. Summary

This article introduces the basic knowledge of using variables in Golang, including variable definition, assignment, scope and constant definition, etc. Variables are an indispensable element in Golang. Understanding and mastering the use of variables is very important for writing efficient and readable code.

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