标签：string water printf star 数组类 before 操作 mod \n
切片是基于数组类型做的一层封装。它非常灵活，可以自动扩容。
var a []int //定义一个int类型的空切片
切片初始化, a[start:end]创建一个包括从start到end-1的切片。
package main import ( "fmt" ) func main() { a := [5]int{76, 77, 78, 79, 80} var b []int = a[1:4] //基于数组a创建?个切?，包括元素a[1] a[2] a[3] fmt.Println(b) }
切片初始化方法2
package main import ( "fmt" ) func main() { c := []int{6, 7, 8} //创建?个数组并返回?个切? fmt.Println(c) }
切片基本操作
a) arr[start:end]：包括start到end-1(包括end-1)之间的所有元素
b) arr[start:]：包括start到arr最后一个元素(包括最后一个元素)之间的所有元素
c) arr[:end]：包括0到end-1(包括end-1）之间的所有元素
d) arr[:]：包括整个数组的所有元素
package main import ( "fmt" ) func testSlice0() { var a []int if a == nil { fmt.Printf("a is nil\n") } else { fmt.Printf("a = %v\n", a) } a[0] = 100 } func testSlice1() { a := [5]int{1, 2, 3, 4, 5} var b []int b = a[1:4] fmt.Printf("slice b:%v\n", b) fmt.Printf("b[0]=%d\n", b[0]) fmt.Printf("b[1]=%d\n", b[1]) fmt.Printf("b[2]=%d\n", b[2]) fmt.Printf("b[3]=%d\n", b[3]) } func testSlice2() { a := []int{1, 2, 3, 4, 5} fmt.Printf("slice a:%v type of a:%T\n", a, a) } func testSlice3() { a := [5]int{1, 2, 3, 4, 5} var b []int b = a[1:4] fmt.Printf("slice b:%v\n", b) // c := a[1:len(a)] c := a[1:] fmt.Printf("slice c:%v\n", c) //d := a[0:3] d := a[:3] fmt.Printf("slice d:%v\n", d) // e := a[0:len(a)] e := a[:] fmt.Printf("slice e:%v\n", e) } func testSlice4() { a := [...]int{1, 2, 3, 4, 5, 7, 8, 9, 11} fmt.Printf("array a:%v type of a:%T\n", a, a) b := a[2:5] fmt.Printf("slice b:%v type of b:%T\n", b, b) /* b[0] = b[0] + 10 b[1] = b[1] + 20 b[2] = b[2] + 30 */ /* for index, val := range b { fmt.Printf("b[%d]=%d\n", index, val) } */ for index := range b { b[index] = b[index] + 10 } fmt.Printf("after modify slice b, array a:%v type of a:%T\n", a, a) } func testSlice5() { a := [...]int{1, 2, 3} s1 := a[:] s2 := a[:] s1[0] = 100 fmt.Printf("a=%v s2=%v\n", a, s2) s2[1] = 200 fmt.Printf("a=%v s1=%v\n", a, s1) } func main() { //testSlice0() //testSlice1() //testSlice2() //testSlice3() //testSlice4() testSlice5() }
package main import ( "fmt" ) func main() { //创建一个数组，其中[…]是编译器确定数组的?度,darr的长度是9 darr := [...]int{57, 89, 90, 82, 100, 78, 67, 69, 59} //基于darr创建一个切片dslice,包括darr[2],darr[3],darr[4]三个元素 dslice := darr[2:5] fmt.Println("array before",darr) for i := range dslice { //对于dslice中每个元素进行+1，其实修改是darr[2],darr[3],darr[4] dslice[i]++ } fmt.Println("array after",darr) }
package main import ( "fmt" ) func main() { numa := [3]int{78, 79 ,80} //创建一个切片，包含整个数组的所有元素 nums1 := numa[:] nums2 := numa[:] fmt.Println("array before change 1",numa) nums1[0] = 100 fmt.Println("array after modification to slice nums1", numa) nums2[1] = 101 fmt.Println("array after modification to slice nums2", numa) }
package main import ( "fmt" ) func main() { //[]中没有长度 i := make([]int, 5, 5) fmt.Println(i) }
package main import ( "fmt" ) func main() { fruitarray := […]string{ "apple", "orange", "grape", "mango", "water melon", "pine apple", "chikoo"} fruitslice := fruitarray[1:3] //长度是2，容量is 6 fmt.Printf("length of slice %d capacity %d", len(fruitslice), cap(fruitslice)) }
package main import "fmt" func testMake1() { var a []int a = make([]int, 5, 10) a[0] = 10 //a[1] = 20 fmt.Printf("a=%v addr:%p len:%d cap:%d\n", a, a, len(a), cap(a)) a = append(a, 11) fmt.Printf("a=%v addr:%p len:%d cap:%d\n", a, a, len(a), cap(a)) for i := 0; i < 8; i++ { a = append(a, i) fmt.Printf("a=%v addr:%p len:%d cap:%d\n", a, a, len(a), cap(a)) } //观察切片的扩容操作，扩容的策略是翻倍扩容 a = append(a, 1000) fmt.Printf("扩容之后的地址：a=%v addr:%p len:%d cap:%d\n", a, a, len(a), cap(a)) } /* a=[10 0 0 0 0] addr:0xc0000860a0 len:5 cap:10 a=[10 0 0 0 0 11] addr:0xc0000860a0 len:6 cap:10 a=[10 0 0 0 0 11 0] addr:0xc0000860a0 len:7 cap:10 a=[10 0 0 0 0 11 0 1] addr:0xc0000860a0 len:8 cap:10 a=[10 0 0 0 0 11 0 1 2] addr:0xc0000860a0 len:9 cap:10 a=[10 0 0 0 0 11 0 1 2 3] addr:0xc0000860a0 len:10 cap:10 a=[10 0 0 0 0 11 0 1 2 3 4] addr:0xc000098000 len:11 cap:20 a=[10 0 0 0 0 11 0 1 2 3 4 5] addr:0xc000098000 len:12 cap:20 a=[10 0 0 0 0 11 0 1 2 3 4 5 6] addr:0xc000098000 len:13 cap:20 a=[10 0 0 0 0 11 0 1 2 3 4 5 6 7] addr:0xc000098000 len:14 cap:20 扩容之后的地址：a=[10 0 0 0 0 11 0 1 2 3 4 5 6 7 1000] addr:0xc000098000 len:15 cap:20 */ func testMake2() { var a []int a = make([]int, 5, 10) //a[5] = 100 a = append(a, 10) fmt.Printf("a=%v\n", a) b := make([]int, 0, 10) fmt.Printf("b=%v len:%d cap:%d\n", b, len(b), cap(b)) b = append(b, 100) fmt.Printf("b=%v len:%d cap:%d\n", b, len(b), cap(b)) } func main() { // testMake1() testMake2() }
package main import "fmt" func reslice() { a := [...]int{1, 2, 3, 4, 5, 6, 4, 7, 8} b := a[2:4] fmt.Printf("b = %d len(b) = %d cap(b)=%d\n", b, len(b), cap(b)) c := b[:cap(b)] fmt.Printf("c = %d len(c) = %d cap(c)=%d\n", c, len(c), cap(c)) } func main() { reslice() } /* b = [3 4] len(b) = 2 cap(b)=7 c = [3 4 5 6 4 7 8] len(c) = 7 cap(c)=7 */
标签：string water printf star 数组类 before 操作 mod \n
原文地址：https://www.cnblogs.com/ctztake/p/10324561.html
