go中的append & delete & copy

slice -> append & copy

map -> delete

//删除map中的数据

func deleteFormMap(){

  mIDMap := make(map[int]string)

mIDMap[0] = “id-1”

mIDMap[1] = “id-2”

delete(mIDMap,key:0)

delete(mIDMap,key:2)

fat.Println(mIDMap) // map[]

}

//拷贝切片

func copyForSlice(){

mIDSliceDst := make([]string,2)

mIDSliceDst[0] = “id-dst-1”

mIDSliceDst[1] = “id-dst-2”

mIDSliceSrc := make([]string,2)

mIDSliceSrc[0] = “id-src-1”

mIDSliceSrc[1] = “id-src-2”

copy(mIDSliceDst,mIDSliceSrc)

fat.Println(mIDSiceDst)  // [id-src-1 id-src-2]

fat.Println(mIDSiceDst)  // [id-src-1 id-src-2 “id-dst-3”]  dst长度为3   src长度为2

fat.Println(mIDSiceDst)  // [id-src-1 id-src-2  ]  dst长度为2   src长度为3

}

//向切片中添加元素并打印出切片的长度和容量

func  appendElementForSlice(){

  mIDSlice := make([]string,2)

mIDSlice[0] = “id -1”

mIDSlice[1] = “id -2”

mIDSlice  =  append(mIDSlice,elems:”id-3”) //[id-1,id-2,id-3]

fat.Println(mIDSlice)

fat.Println(a:”len=”,len(mIDSlice))   //len = 3

fat.Println(a:”cap”,cap(mIDSlice))  // cap = 4

}