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Editor to share with you the example analysis of variable declaration and assignment in go language, I believe that most people do not know much about it, so share this article for your reference, I hope you can learn a lot after reading this article, let's go to know it!

Variable

A variable is an abstract description of a space in memory. The type of variable defines the size of the space and how it is parsed.

Variable type 1 in Go

Bool byte complex64 complex128 error float32 float64 int int8 int16 int32 int64 rune string uint uint8 uint16 uint32 uint64 uintptr

Declaration and assignment of variables 11

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Package main

Import "fmt"

Func main () {

Var x string

X = "Hello World"

Fmt.Println (x)

}

Mode 2

Note that x: = "Hello World" is equivalent to var x = "Hello World"

Automatically infers the type and must be inside the function body

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Package main

Import "fmt"

Func main () {

X: = 1

Fmt.Println (x)

}

Multiple assignments 1

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Var i int

Var U, V, W float64

Var k = 0

Var x, y float32 =-1,-2

Var (

I int

U, v, s = 2.0,3.0, "bar"

)

Example:

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Package main

Import "fmt"

Func main () {

Var a string= "jonson", "jackson"

C true,false d: =

Erecent fjorg: = "jonson", true,123

Fmt.Println ("a:", a)

Fmt.Println ("b:", b)

Fmt.Println ("c:", c)

Fmt.Println ("d:", d)

Fmt.Println ("e:", e)

Fmt.Println ("f:", f)

Fmt.Println ("g:", g)

}

Zero value problem

If the variable initialization does not assign a value, the default is empty.

Example:

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Package main

Import "fmt"

Func main () {

Var an int

Var b string

Var c float64

Var d bool

Fmt.Printf ("% v\ n", a)

Fmt.Printf ("% v\ n", b)

Fmt.Printf ("% v\ n", c)

Fmt.Printf ("% v\ n", d)

Fmt.Println ()

}

Constant

Once a constant is declared, it cannot be changed, and the constant must be assigned an initial value. This code is invalid func main () {const x int}

Valid:

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Package main

Const (

M = 1

N = 2

)

Func main () {

Const k = 8

}

Iota usage

Iota loops from 0

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Const (

A = iota

B = iota

C = iota

D = iota

)

Equivalent to:

Const (

A = iota

B

C

D

)

Use case:

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Package main

Import "fmt"

Func main () {

Const (

A = iota / / 0

B / / 1

C / / 2

D = "ha" / / Independent value, iota + = 1

E / / "ha" iota + = 1

F = 100 / / iota + = 1

G / / 100 iota + = 1

H = iota / / 7, restore count

I / / 8

)

Fmt.Println (a recalcitrance brecrium crecinct d recorder e recorder f g jiggy pr I)

}

Abnormal iota1

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Package main

Import "fmt"

Const (

I, 1

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