Go语言--切片(Slice)详解

var identifier []type
//例如
var slice []int

var slice1 []type = make([]type, len)
//也可以简写为
slice1 := make([]type, len)
//例如
slice := make([]type, len)

package main

import "fmt"

func main(){
    var number = make([]int,3,5)
    fmt.Printf("len=%d cap=%d         slice=%v\n",len(number),cap(number),number)
}

//len=3 cap=5 slice=[0 0 0]

package main

import "fmt"

func main(){
    var number []int
    fmt.Printf("len=%d cap=%d slice=%v\n",len(number),cap(number),number)
}

//len=0 cap=0 slice=[]

package main

import "fmt"

func main() {
    //创建切片
    number := []int{0, 1, 2, 3, 4, 5, 6, 7, 8}
    printSlice(number)

    //打印原始切片
    fmt.Println("number == ", number)

    //打印子切片从索引1到索引4
    fmt.Println("number == ", number[1:4])

    //打印子切片默认下限
    fmt.Println("number == ", number[:3])

    //打印子切片默认上限
    fmt.Println("number == ", number[4:])

}

func printSlice(x []int) {
    fmt.Printf("len=%d cap=%d slice=%v\n", len(x), cap(x), x)
}

append() 和 copy() 函数
package main

import (
    "fmt"
)

func main() {
    //创建切片
    var number []int
    printSlice(number)

    //允许追加空切片
    number = append(number,0)
    printSlice(number)

    //向切片添加一个元素
    number = append(number,1)
    printSlice(number)

    //同时添加多个元素
    number = append(number,2,3,4)
    printSlice(number)

    //创建的新的切片是之前的切片容量的两倍
    number1 := make([]int,len(number),(cap(number))*2)

    //拷贝number的内容到number1中
    copy(number1,number)
    printSlice(number1)
}

func printSlice(x []int) {
    fmt.Printf("len=%d cap=%d slice=%v\n", len(x), cap(x), x)
}