Go中Slice的使用
摘要:// code_013_slice_usage project main.go
package main
import (
"fmt"
)
func test(s []int) {
s[0] = -1
fmt.Println("test:"...
// code_013_slice_usage project main.go package main import ( "fmt" ) func test(s []int) { s[0] = -1 fmt.Println("test:") for i, v := range s { fmt.Printf("s[%d]=%d\n", i, v) } fmt.Println("\n") } func main() { //var s1 []int //s2 := []int //var s3 []int = make([]int ,0) //s4 :=make([]int, 0, 0) s := []int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9} s1 := s[2:5] fmt.Println(s1) s2 := s1[2:6] s2[3] = 200 fmt.Println(s2) fmt.Println(s) //內建函式的使用 //1)append函式向slice尾部新增資料,返回新的slice物件 var ss []int ss = append(ss, 1) ss = append(ss, 2, 3) ss = append(ss, 4, 5, 6) fmt.Println(ss) ss2 := make([]int, 5) ss2 = append(ss2, 6) fmt.Println(ss2) ss3 := []int{1, 2, 3} ss3 = append(ss3, 4, 5) fmt.Println(ss3) //append函式會智慧地底層陣列的容量增長,一旦超過原底層陣列容量 //通常以2倍容量重新分配底層陣列,並複製原來的資料 sss := make([]int, 0, 1) c := cap(sss) for i := 0; i < 50; i++ { sss = append(sss, i) if n := cap(sss); n > c { fmt.Printf("cap:%d -> %d\n", c, n) c = n } } //copy //函式copy在兩個slice間賦值資料 //賦值長度以len小為準,兩個silce可指向同一底層陣列 data := [...]int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9} v1 := data[8:] //{8, 9} v2 := data[:5] //{0, 1, 2, 3, 4} copy(v2, v1)// dst:s2, src:s1 fmt.Println(v2)//[8 9 2 3 4] fmt.Println(data) //[8 9 2 3 4 5 6 7 8 9] //切片做函式引數 slice := []int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9} test(slice) fmt.Println("main:") for i, v := range slice { fmt.Printf("slice[%d]=%d\n", i, v) } //備註:底層陣列的值被改變了。 fmt.Println("\n") }