Go数组 切片 映射
Livingbody 人气:0Arrays (数组), Slices (切片) 和 Maps (映射) 是常见的一类数据结构
1.Arrays (数组)
- 数组是定长的。
- 长度不可改变。
初始化
package main import ( "fmt" ) func main() { var scores [10]int scores[0] = 99 fmt.Printf("scoers:%d\n", scores) socres_english := [4]int{99, 100, 100, 99} for index, value := range socres_english { fmt.Printf("%d\t %d", index, value) } }
Starting: C:\Users\livingbody\go\bin\dlv.exe dap --check-go-version=false --listen=127.0.0.1:14487 from c:\Users\livingbody\goworkspace\hello
DAP server listening at: 127.0.0.1:14487
Type 'dlv help' for list of commands.
scoers:[99 0 0 0 0 0 0 0 0 0]
0 991 1002 1003 99
Process 14356 has exited with status 0
Detaching
dlv dap (15128) exited with code: 0
2.切片
切片是轻量的包含并表示数组的一部分的结构。
2.1 make创建切片
# 即创建长度10,容量0的切片 score := make([]int, 0, 10)
- 切片后可以通过append赋值
- 切片可以重新切片,然后通过索引赋值
- 切片超过容量会自动增大,自身倍数
package main import ( "fmt" ) func main() { var scores [10]int scores[0] = 99 fmt.Printf("scoers:%d\n", scores) socres_english := [4]int{99, 100, 100, 99} for index, value := range socres_english { fmt.Printf("%d\t %d\n", index, value) } score_math := make([]int, 0, 10) score_math = append(score_math, 100) fmt.Println(score_math) fmt.Println(score_math[0]) score_math = score_math[0:8] score_math[7] = 99 fmt.Println(score_math) c := cap(score_math) fmt.Println(c) for i := 0; i < 25; i++ { score_math = append(score_math, i) if cap(score_math) != c { c = cap(score_math) fmt.Println(c) } } }
输出:
Type 'dlv help' for list of commands.
scoers:[99 0 0 0 0 0 0 0 0 0]
0 99
1 100
2 100
3 99
[100]
100
[100 0 0 0 0 0 0 99]
10
20
40
Process 20448 has exited with status 0
Detaching
dlv dap (7204) exited with code: 0
3.映射Map
就好比其他语言中的 hash 表或者字典。它们的工作方式就是:定义键和值,并且可以获取,设置和删除其中的值。
同样通过make方法创建。
package main import ( "fmt" ) func main() { lookup := make(map[string]int) lookup["goku"] = 9001 power, exists := lookup["vegeta"] fmt.Println(power, exists) total := len(lookup) fmt.Println(total) delete(lookup, "goku") fmt.Println(len(lookup)) }
Starting: C:\Users\livingbody\go\bin\dlv.exe dap --check-go-version=false --listen=127.0.0.1:14812 from c:\Users\livingbody\goworkspace\hello
DAP server listening at: 127.0.0.1:14812
Type 'dlv help' for list of commands.
0 false
1
0
Process 924 has exited with status 0
Detaching
dlv dap (700) exited with code: 0
迭代
for key, value := range lookup { ... }
注意:
map迭代没有顺序
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