Go language self-study series | go language data type

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stay Go In programming language , Data types are used to declare functions and variables .

The emergence of data types is to divide the data into the required data types Memory size Different data , When programming, you need to use big data to apply for large memory , You can make full use of memory .

Go Languages have the following data types by category ：

Serial number	Type and description
1	Boolean type Boolean values can only be constants true perhaps false. A simple example ：var b bool = true.
2	Numeric type integer int And floating point float32、float64,Go The language supports integer and floating-point numbers , And support plural , The operation of the middle bit adopts complement .
3	String type : A string is a sequence of characters connected by a fixed length of characters .Go A string of strings is concatenated by a single byte .Go Language string byte use UTF-8 Code identification Unicode Text .
4	Derived type : Include ：(a) Pointer types （Pointer）(b) An array type (c) Structured type (struct)(d) Channel type (e) Function type (f) Slice type (g) Interface type （interface）(h) Map type

Numeric type

Go There are also architecture based types , for example ：int、uint and uintptr.

Serial number	Type and description
1	uint8 Unsigned 8 An integer (0 To 255)
2	uint16 Unsigned 16 An integer (0 To 65535)
3	uint32 Unsigned 32 An integer (0 To 4294967295)
4	uint64 Unsigned 64 An integer (0 To 18446744073709551615)
5	int8 A signed 8 An integer (-128 To 127)
6	int16 A signed 16 An integer (-32768 To 32767)
7	int32 A signed 32 An integer (-2147483648 To 2147483647)
8	int64 A signed 64 An integer (-9223372036854775808 To 9223372036854775807)

floating-point

Serial number	Type and description
1	float32 IEEE-754 32 Bit floating point number
2	float64 IEEE-754 64 Bit floating point number
3	complex64 32 Bit real number and imaginary number
4	complex128 64 Bit real number and imaginary number

Other number types

Here are more types of numbers ：

Serial number	Type and description
1	byte similar uint8
2	rune similar int32
3	uint 32 or 64 position
4	int And uint The same size
5	uintptr Unsigned integer , Used to store a pointer

give an example

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       package main
       
       

       
       
import "fmt"
       
       

       
       
func a3() {
       
       

       
       
}
       
       

       
       
func main() {
       
       
    var name string = "tom"
       
       
    age := 20
       
       
    b := true
       
       
    fmt.Printf("name: %T\n", name)
       
       
    fmt.Printf("age: %T\n", age)
       
       
    fmt.Printf("b: %T\n", b)
       
       

       
       
    a := 100
       
       
    p := &a
       
       
    fmt.Printf("p: %T\n", p)
       
       

       
       
    a1 := [2]int{1, 2}
       
       
    fmt.Printf("a1: %T\n", a1)
       
       

       
       
    a2 := []int{1, 2, 3}
       
       
    fmt.Printf("a2: %T\n", a2)
       
       

       
       
    fmt.Printf("a3: %T\n", a3)
       
       

       
       
}
      
      
      
      

       
       
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Running results

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       [Running] go run "d:\SynologyDrive\ software development \go\golang Introduction to project practice \goproject\360duote.com\pro01\contant.go"
       
       
name: string
       
       
age: int
       
       
b: bool
       
       
p: *int
       
       
a1: [2]int
       
       
a2: []int
       
       
a3: func()
      
      
      
      

       
       
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