GO语言：指针

package main

import "fmt"

func main(){
	var num = 10
	var p = &num
	//var p *int = &num
	//p := &num
	
	fmt.Println(*p)
}

package main

import "fmt"

func main(){
	var ptr *int //空指针

	if ptr == nil {
		fmt.Println(ptr)
	}
	if ptr != nil {
		fmt.Println(ptr)
	}
}

package main

import "fmt"

func main(){
	var arr = []int{1, 2, 3}
	var ptrArr[3] *int //不初始化则只能明确数组元素的数量

	for i := 0; i < len(arr); i++ {
		ptrArr[i] = &arr[i]
	}

	fmt.Println(ptrArr)
}