go 變量篇

go 變量篇

package main

import "fmt"

func main() {
	//1.聲明單個變量  var name type
	var age int
	fmt.Println("hello world", age)
	age = 28
	fmt.Println("hello world", age)
	age = 54
	fmt.Println("hello world", age)

	//2.聲明變量並初始化  var name type = initialvalue
	var name string = "張三"
	fmt.Println("name: ", name)

	//3.類型推斷 如果變量有初始值，可以根據變量的值，自動推斷出變量的類型，可以省略變量類型的書寫
	var sex = 1
	fmt.Println("sex: ", sex)

	//4.聲明多個變量
	//var name1,name2 type = ini11,init2
	var height, weight = 175, 60
	fmt.Println("height: ", height, "weight: ", weight)

	//定義 但是沒有初始化
	var height2, weight2 int
	fmt.Println("height2: ", height2, "weight2: ", weight2)
	//對變量進行賦值
	height2 = 170
	weight2 = 80
	fmt.Println("height2: ", height2, "weight2: ", weight2)

	//5.在語句中申明不同的變量  var (
	//   name1=init1
	//   name2=init2
	// )

	var (
		color = "紅色" //string
		money = 12   //int
	)
	fmt.Println("color: ", color, "money: ", money)

	//6 := 簡短的聲明變量的形式
	a, b := 10, 20
	fmt.Println("a: ", a, "b: ", b)
	//go中=和:=的區別
	//=是賦值  := 是聲明並賦值

}