Golang Learning Notes-1.3 variables

This article is the third Golang language learning tutorial
The Var declaration statement can create a variable of a specific type, then append a name to the variable and set the initial value of the variable.
The variable declaration syntax is as follows :

var variable name type = Expression

Cases:

var age int = 19

where "type" or "= expression" Two can omit one of the two.

If the type is omitted, the type information is determined based on the initial expression.
If the = Expression is omitted, the variable is initialized with a value of 0.

Example 1:

package mainimport "fmt"func main() {        var age = 19 //省略类型，根据自动表达式确定age类型        fmt.Println("Hello World,my age is",age)}

The above program will print:

Hello World,my Age is 19

Example 2:

package mainimport "fmt"func main(){    var age int //省略表达式，默认用0初始化该变量    fmt.Println("Hello World,my age is",age)}

The above program will print:

Hello World,my Age is 0

Declaring multiple variables

Go is able to declare multiple variables through a single statement.
The syntax for declaring multiple variables is as follows :

var name1, name2 type = initialvalue1, initialvalue2

Cases:

package mainimport "fmt"func main(){        var height,weight = 178,57 //声明两个变量身高，体重        fmt.Println("my height is",height,"and my weight is",weight)}

The above program will print:

My height is 178 and my weight is 57

In some cases we may need to declare variables of different types in one statement.
A statement declares different types of variable syntax as follows :

var (   name1 = initialvalue1   name2 = initialvalue2)例：```gopackage mainimport "fmt"func main(){       var (           name = "xunk"           age = 19           height = 178       )       fmt.Println("my name is",name,",my age is",age,"and my heiget is",height)}

The above program will print:

My name is Xunk, my age was and my heiget is 178

Brief statement

Go supports a concise way of declaring variables, using the: = operator, called a short declaration.
The short declaration syntax is as follows:

Name: = InitialValue

Cases:

package mainimport "fmt"func main(){        name,age := "xunk",19 //简短声明name,age        fmt.Println("my name is",name,"my age is",age)}

The above program will print:

My name is Xunk my 19

: = Short declaration All variables on the left have an initial value, and the left side of the operator must have a variable that is not yet declared.

Variables can also be assigned at run time.
Cases:

package mainimport (        "fmt"        "math")func main(){        a,b := 25.3,73.1 //声明a,b变量        c := math.Min(a,b) //比较a,b最小值，赋值给c        fmt.Println("The minimum values is",c)}

The above program will print:

The minimum values is 25.3

Because Go is a strongly typed (strongly Typed) language, a variable of one type is not allowed to be assigned a value of another type.

package mainfunc main() {      age := 29      // age是int类型    age = "naveen" // 错误，尝试赋值一个字符串给int类型变量}

The above procedure will be error:

(type string) as type int in assignment

You cannot assign a string to an int type variable