golang数组声明

格式

初始化数组 {}中的元素数不能大于[]中的数字，并且长度在初始化后不能改变，定义数组时需指定长度 ...

var arrName [num]type = [num]type{value, value, value,....}

在函数调用时, 数组是值传递，而分片是引用传递

其实对于go来说，函数调用的时候都是值传递，拷贝一个副本， 切片本身它就是指针

var (
	arr1   = [3]int{1, 2, 3}
	slice1 = []int{1, 2, 3, 4, 5}
)

func arr(array [3]int) {
	fmt.Printf("%p\n", &arr1)
	fmt.Printf("%p\n", &array)
}

func slicep(slice2 []int) {
	fmt.Printf("%p\n", slice1)
	fmt.Printf("%p\n", slice2)
}

func main() {
	arr(arr1)
	slicep(slice1)
}

数组，多维数组生成方式

func main() {
	var a [5]int
	var a1 = [...]string{"a", "b"}
	var a2 = [...]int{1, 2, 3, 4, 5, 6, 7}
	var a3 = [...][2]int{
		{1, 2},
		{4, 5},
	}
	var a4 [3][5]string = [...][5]string{
		{"a", "b"},
		{"c", "d"},
		{"f", "g"},
	}
}

注意：...在一行只能用一次，否则会报 use of [...] array outside of array literal

var a4 [3][5]string = [...][5]string{
	{"a", "b"},
	{"c", "d"},
	{"f", "g"},
	{"f", "g"},
}

var a4 [...][5]string = [...][5]string{
	{"a", "b"},
	{"c", "d"},
	{"f", "g"},
	{"f", "g"},
}

数组是值类型，改变的是副本的值，不会改变本身的值

package main

import (
	"fmt"
)

func main() {
	var a = [...]int{1, 2, 4, 5, 6}

	var b = a

	b[1] = 10000

	fmt.Println(a)
	fmt.Println(b)

}

练习：使用数组打印斐波那契数列

package main

import (
	"fmt"
)

func calc(n int) []int64 {
	var a []int64
	a = make([]int64, n)

	a[0] = 1
	a[1] = 1

	for i := 2; i < n; i++ {
		a[i] = a[i-1] + a[i-2]
	}
	return a
}

func main() {
	var test = calc(10)

	fmt.Println(test)
}