go语言深拷贝和浅拷贝 go语言

%T ：使用Go语法输出的值的类型
%v：使用默认格式输出的内置或者自定义类型的值，或者是使用其类型的String()方式输出的自定义值，如果该方法存在的话
%p：以十六进制(基数为16)表示的一个值的地址，前缀为0x,字母使用小写的a-f表示
1、浅复制（1）new()和:=

package mainimport "fmt"type dog struct { name string ageint sexint }func main() { dog1 := new(dog) dog1.name = "dog1" dog1.age = 11 dog1.sex = -1 dog2 := dog1 fmt.Printf("%T %v %p\n", dog1, dog1, dog1) fmt.Printf("%T %v %p\n", dog2, dog2, dog2) dog2.name = "dog2" dog2.age = 12 dog2.sex = 2 fmt.Printf("%T %v %p\n", dog1, dog1, dog1) fmt.Printf("%T %v %p\n", dog2, dog2, dog2) }

文章图片

2、浅复制（2）结构名{}和 :=&

package mainimport "fmt"type dog struct { name string ageint sexint }func main() { dog1 := dog{ name: "dog1", age:11, sex:-1, } dog2 := &dog1 fmt.Printf("%T %v %p\n", dog1, dog1, dog1) fmt.Printf("%T %v %p\n", dog2, dog2, dog2) dog2.name = "dog2" dog2.age = 12 dog2.sex = 2 fmt.Printf("%T %v %p\n", dog1, dog1, dog1) fmt.Printf("%T %v %p\n", dog2, dog2, dog2) }

文章图片

3、浅复制（3）切片

package mainimport ( "fmt" "unsafe" )func main() { slice_test := []int{1, 2, 3, 4, 5} fmt.Println(unsafe.Sizeof(slice_test)) fmt.Printf("main:%#v,%#v,%#v\n", slice_test, len(slice_test), cap(slice_test)) slice_value(slice_test) fmt.Printf("main:%#v,%#v,%#v\n", slice_test, len(slice_test), cap(slice_test)) slice_ptr(&slice_test) fmt.Printf("main:%#v,%#v,%#v\n", slice_test, len(slice_test), cap(slice_test)) fmt.Println(unsafe.Sizeof(slice_test)) }func slice_value(slice_test []int) { slice_test[1] = 100// 函数里的slice确实有被修改 slice_test = append(slice_test, 6) // 函数外的不变 fmt.Printf("slice_value:%#v,%#v,%#v\n", slice_test, len(slice_test), cap(slice_test)) }func slice_ptr(slice_test *[]int) { // 这样才能修改函数外的slice (*slice_test)[1] = 10 *slice_test = append(*slice_test, 7) fmt.Printf("slice_ptr:%#v,%#v,%#v\n", *slice_test, len(*slice_test), cap(*slice_test)) }

文章图片

unsafe.sizeof()
4、深复制（1）结构名{}和:=

package mainimport "fmt"type dog struct { name string ageint sexint }func main() { dog1 := dog{ name: "dog1", age:11, sex:-1, } dog2 := dog1 fmt.Printf("%T %v %p\n", dog1, dog1, dog1) fmt.Printf("%T %v %p\n", dog2, dog2, dog2) dog2.name = "dog2" dog2.age = 12 dog2.sex = 2 fmt.Printf("%T %v %p\n", dog1, dog1, dog1) fmt.Printf("%T %v %p\n", dog2, dog2, dog2) }

【go语言深拷贝和浅拷贝】