enabled { // Only shade the pointers in old.array since we know the destination slice p // only contains nil pointers because it has been cleared during alloc. bulkBarrierPreWriteSrcOnly(uintptr(p), uintptr(old.array), lenmem-et.size+et.ptrdata) } } // 将 lenmem 这个多个 bytes 从...
不止是函数传递,包括slice的复制,同样也是只拷贝slice的结构体,共用底层的数据,所以复制出来的切片修改数据也会影响到原值。 来个小图吧。 五、 map 同样先看看官网博客的定义: Go provides a built-in map type that implements a hash table. Map types are reference types, like pointers or slices. 也就...
} else { // Note: can't use rawmem (which avoids zeroing of memory), because then GC can scan uninitialized memory. p = mallocgc(capmem, et, true) if lenmem > 0 && writeBarrier.enabled { // Only shade the pointers in old.array since we know the destination slice p ...
slice := make([]int, 1, 10) fmt.Printf(“addres1: %p\n”, &slice) someChage(slice) package main
string->""pointers ->nil slices ->nil maps ->nil channels ->nil functions ->nil interfaces ->nil 4、切片的循环遍历 切片的循环遍历和数组的循环遍历是一样的 vara = []string{"北京","上海","深圳"} // 方法 1:for 循环遍历 fori :=0; i <len(a); i++ { ...
在Go语言中,slice(切片)是Gopher开发中最常用到的一种数据结构,又称为动态数组,其长度并不固定,我们可以向切片中追加元素,它会在容量不足时自动扩容。本文将结合Go1.15源码 + windows amd64位机,对slice的底层实现进行深入剖析。 slice创建 在Go语言中,创建切片的方式有一下几种 : ...
capmem=roundupsize(uintptr(newcap)*et.size)newcap=int(capmem/et.size)}// 判断非法的值,保证容量是在增加,并且容量不超过最大容量ifcap<old.cap||uintptr(newcap)>maxSliceCap(et.size){panic(errorString("growslice: cap out of range"))}varp unsafe.Pointerifet.kind&kindNoPointers!=0{// 在...
capmem=roundupsize(uintptr(newcap)*et.size)newcap=int(capmem/et.size)}...varp unsafe.Pointerifet.kind&kindNoPointers!=0{//这里有个优化细节,先不zero,因为前部会发生覆盖p=mallocgc(capmem,nil,false)memmove(p,old.array,lenmem)//只对后部zeromemclrNoHeapPointers(add(p,newlenmem),capmem...
slice1 := make([]int,1,) fmt.Println("cap of slice1",cap(slice1)) slice1 = append(slice1,1) fmt.Println("cap of slice1",cap(slice1)) slice1 = append(slice1,2) fmt.Println("cap of slice1",cap(slice1)) fmt.Println() ...
slice3 := []int{1,3,7,5,2,3,4} fmt.Println(slice3[1]) // 3 fmt.Println(slice3[10]) // 运行时报panic: runtime error: index out of range [10] with length 7 1. 2. 3. 4. 5. for循环操作 slice3 := []int{1,3,7,5,2,3,4} ...