golang append時(shí)slice len 和 cap
Posted on 2013-11-20 18:48 oathleo 閱讀(5266) 評(píng)論(1) 編輯 收藏 所屬分類(lèi): Golang聲明:
源slice= src
添加slice = app
結(jié)果slice=tar
append時(shí)
len tar === len src + len app
1)如果len(src) + len(app) <= cap(src) cap tar = cap(src)
2)否則
a) len(src) + len(app) > 2* cap(src) cap tar = len(src) + len(app)
b) cap(src) < len(src) + len(app) <= 2* cap(src) cap tar = 2* cap(src)
data := make([]int, 10, 20)
data[0] = 1
data[1] = 2
dataappend := make([]int, 12, 30)//修改這個(gè)len
dataappend[0] = 1
dataappend[1] = 2
result := append(data, dataappend
)
result[0] = 99
result[11] = 98
fmt.Println("length:", len(data), "cap:", cap(data), ":", data)
fmt.Println("result length:", len(result), "cap:", cap(result), ":", result)
fmt.Println("length:", len(dataappend), "cap:", cap(dataappend), ":", dataappend)
data[0] = 1
data[1] = 2
dataappend := make([]int, 12, 30)//修改這個(gè)len
dataappend[0] = 1
dataappend[1] = 2
result := append(data, dataappend

result[0] = 99
result[11] = 98
fmt.Println("length:", len(data), "cap:", cap(data), ":", data)
fmt.Println("result length:", len(result), "cap:", cap(result), ":", result)
fmt.Println("length:", len(dataappend), "cap:", cap(dataappend), ":", dataappend)