Video source ：B standing 《golang Introduction to project practice [2021 newest Go Language course , There is no nonsense , Dry only ！ Ongoing update ...]》

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Before introducing the structure , Let's first look at what type definitions and type aliases are .

go Language type definition

Syntax of type definition

type NewType Type

example

package main

import "fmt"

func main() {
    //  The type definition 
    type MyInt int
    // i by MyInt type 
    var i MyInt
    i = 100
    fmt.Printf("i: %v i: %T\n", i, i)
}

Running results

[Running] go run "/Users/guoliang/SynologyDrive/ software development /go/golang Introduction to project practice /goproject/360duote.com/pro01/test.go"
i: 100 i: main.MyInt

go Language type alias

Syntax of type aliases

type NewType = Type

example

package main

import "fmt"

func main() {
    //  Type alias definition 
    type MyInt2 = int
    // i In fact, or int type 
    var i MyInt2
    i = 100
    fmt.Printf("i: %v i: %T\n", i, i)
}

go The difference between language type definition and type alias

1. Type definition is equivalent to defining a new type , Different from the previous type ; But the type alias does not define a new type , Instead, use an alias to replace the previous type
2. Type aliases will only exist in code , The alias does not exist after compilation
3. Because the type alias is consistent with the original type , So the methods owned by the original type , You can also call... In the type alias , But if it's a redefined type , Then you can't call any of the previous methods