Types of GoLang

[TOC]

• bool

• Numeric Types

  • int8, int16, int32, int64, int
  • uint8, uint16, uint32, uint64, uint
  • float32, float64
  • complex64, complex128
  • byte
  • rune

• String

Bool

bool type represents a boolean, either true or false

package main

import "fmt"

func main(){
    a := true
    b := false
    fmt.Println("boolean a:",a ,"b:",b)
    c := a && b
    d := a || b
    fmt.Println(c, d)
}

a is assigned true, b is assigned false, c is assigned a && b, d is assigned a || b&&是逻辑运算符 and, ||是逻辑运算符 or, !是逻辑运算符 not; 所以运行above program 会得到如下结果;

image

Signed integers

int

通常情况是都使用int表示整数, 除非需要表示特定大小的整数; int 的大小和范围取决于底层操作系统;

验证int类型

package main

import (
    "fmt"
    "unsafe"
)

func main() {
    variable_a := 18
    var variable_b int = 183
    fmt.Printf("type: %T\t%T", variable_a, variable_b) //打印两个变量的类型
    fmt.Printf("\nSize: %d\t%d", unsafe.Sizeof(variable_a), unsafe.Sizeof(variable_b))
} //输出两个变量的大小 

得到输出如下, 我使用的是64 bits Linux-Manjaro Desktop, 所以验证变量大小是输出为8; 如果是32为的电脑unsafe.Sizeof() 输出结果为 4.

image

No signed integers

| | uint8 | uint16 | uint32 | uint64 | uint |
|-:-|:-:|:-:|:-:|:-:|:-:|
| Size | 8 bits | 16 bits | 32 bits | 64 bits | 32 or 64 |
| Range | 0 - 255 | 0 - 65535 | 0 - 4294967295 | 0 - 1844073709551615 | uint 32 or uint 64 |

Floating point types

float 32

32 bit floating point numbers

float 63

64 bit floating point numbers

Complex types

complex64

具有float32实部和float32虚部的复数数字

complex128

具有float64实部和float64虚部的复数数字

byte

byte就是uint8 的别名

rune

rune 是 int32的别名

强制类型转换

go 对显示输入非常严格. 没有自动\隐性类型转换

package main

import (
    "fmt"
    "math"
)

func main() {
    a := 3
    b := 4
    var c int
    c = int(math.Sqrt(float64(a*a + b*b)))
    fmt.Println(c)
}

因为math.Sqrt()需要传入float64, 返回的也是float64 所以这里必须手动强制进行转换 否则编译错误;