slice1 := make([]int, 1, 10) ptr := unsafe.Pointer(&slice1) opt := (*[3]int)(ptr) ...
funcprintslice(nstring,s*[]string){typeSliceStructstruct{ptruintptrlenuint64capuint64}p:=(*SliceStruct)(unsafe.Pointer(s));ifn=="s1"{p.cap=2// rewrite cap to 2 for s1 slice by force}fmt.Printf("%s: p=%p,ptr=0x%x,len=%d,cap=%d,val=%v\n",n,p,p.ptr,p.len,p.cap,s)} 再...
slice只是一个结构体，里面存了底层数组的ptr，cap以及本身的len，底层数组重新分配地址只是改变了slice...
The slice that we created above is not an actual slice, but rather a description of an array that could be represented as ( theoretically ) typeslicestruct{LengthintCapacityintfirstElement*int(or pointer to underlying array)} We know that each slice has three attributes,length,capacity, andpoin...
// The make built-in function allocates and initializes an object of type// slice, map, or chan (only). Like new, the first argument is a type, not a// value. Unlike new, make's return type is the same as the type of its// argument, not a pointer to it. The specification ...
而golang也有这样的划分,基本类型(Golang学习系列第二天已学过)和派生类型(不叫引用类型),派生类型有以下几种:数组类型、切片类型、Map类型、结构体类型(struct)、指针类型(Pointer)、函数类型、接口类型(interface)、Channel 类型。 1. 数组类型 数组是具有相同数据类型的元素序列。 数组在声明中定义了固定的长度,...
Slice 切片即动态数组,可以动态扩容改变数组的容量. golang 的 slice 底层结构如下所示,它是一个结构体,里面包含了指向数组的地址,并通过 len、cap 保存数组的元素数、容量: type slice struct { array unsafe.Pointer // 指向数组的指针
= a[lo:hi]// creates a slice (view of the array) from index lo to hi-1var b = a[1:4]// slice from index 1 to 3var b = a[:3]// missing low index implies 0var b = a[3:]// missing high index implies len(a)a =append(a,17,3)// append items to slice ac :=append...
append 向slice里面追加一个或者多个元素,然后返回一个和slice一样类型的slice copy 函数copy从源slice的src中复制元素到目标dst,并且返回复制的元素的个数注:append函数会改变slice所引用的数组的内容,从而影响到引用同一数组的其它slice。 但当slice中没有剩余空间(即(cap-len) == 0)时,此时将动态分配新的数组空...
slice是一个结构体 参照源码: src/runtime/slice.go golang typeslicestruct{ array unsafe.Pointerlenintcapint} array:数组指针,len表示长度,cap表示容量 切片的声明 golang vara []int 采用数组创建切片 golang vara = [10]int{1,2,3,4,5,6,7,8,9} ...