add array sample

sample-golang / 01_hello

Browse code add array sample master
1 parent b17086f commit a1e938df450a3388c9f565b78d5b6d8bded63a24 yhornisse authored on 24 Sep 2021

Patch

Showing 10 changed files

Ignore Space Show notes View args.go
package main import ( "fmt" "os" "strings" ) func main() { fmt.Printf("args: %+v\n", os.Args) fmt.Printf("args: %+v\n", os.Args[1:]) fmt.Printf("args: %s\n", strings.Join(os.Args[1:], ",")) } package main import ( "fmt" "os" "strings" ) func main() { fmt.Printf("args: %+v\n", os.Args) fmt.Printf("args: %+v\n", os.Args[1:]) fmt.Printf("args: %s\n", strings.Join(os.Args[1:], ",")) }

Ignore Space Show notes View array.go 0 → 100644
package main import "fmt" func main() { var a[3]int // 要素の値を省略したらゼロ値 fmt.Printf("a: %+v\n", a) // [0, 0, 0] b := [3]int{1, 2, 3} fmt.Printf("b: %+v\n", b) // [1, 2, 3] c := [3]int{1, 2} fmt.Printf("c: %+v\n", c) // [1, 2, 0] d := [3]int{2: 2} fmt.Printf("d: %+v\n", d) // [0, 0, 2] e := [3]int{0:1, 1: 2} fmt.Printf("e: %+v\n", e) // [1, 2, 0] // 要素が比較可能であればその配列型も比較可能 fmt.Printf("a==b: %v\n", a == b) // false fmt.Printf("c==e: %v\n", c == e) // true // f := [4]int{} // fmt.Printf("a==f: %v\n", a == f) // compile error: [3]int == [4]int hoge(a) fmt.Printf("a: %+v\n", a) // [0, 0, 0] } func hoge(arg [3]int) { arg[0] = 4 fmt.Printf("%+v\n", arg) // [4, 0, 0] // 値渡しなので安全だが性能的に非効率なことがある }

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array.go 0 → 100644

Ignore Space Show notes View array/README.md 0 → 100644
## array.go 配列 ## slice.go スライス ## append.go append関数の使い方や仕組み

Ignore Space Show notes View array/append 0 → 100755
Not supported

Ignore Space Show notes View array/append.go 0 → 100644
package main import "fmt" func main() { ary := []int{} for i := 0; i < 10; i++ { ary = append(ary, i) fmt.Printf("%d: %p len:%d cap:%d %v\n", i, ary, len(ary), cap(ary), ary) } /* 0: 0x140000180b8 len:1 cap:1 [0] 1: 0x140000180e0 len:2 cap:2 [0 1] 2: 0x1400001e040 len:3 cap:4 [0 1 2] 3: 0x1400001e040 len:4 cap:4 [0 1 2 3] 4: 0x14000014100 len:5 cap:8 [0 1 2 3 4] 5: 0x14000014100 len:6 cap:8 [0 1 2 3 4 5] 6: 0x14000014100 len:7 cap:8 [0 1 2 3 4 5 6] 7: 0x14000014100 len:8 cap:8 [0 1 2 3 4 5 6 7] 8: 0x1400006e000 len:9 cap:16 [0 1 2 3 4 5 6 7 8] 9: 0x1400006e000 len:10 cap:16 [0 1 2 3 4 5 6 7 8 9] */ }

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array/append.go 0 → 100644

Ignore Space Show notes View array/append.go~ 0 → 100644
package main import "fmt" func main() { ary := []int{} for i := 0; i < 10; i++ { ary = append(ary, i) fmt.Printf("%d: %p cap:%d %v\n", i, ary, cap(ary), ary) } /* 0: 0x14000134008 cap:1 [0] 1: 0x14000134030 cap:2 [0 1] 2: 0x1400013a020 cap:4 [0 1 2] 3: 0x1400013a020 cap:4 [0 1 2 3] 4: 0x1400012c080 cap:8 [0 1 2 3 4] 5: 0x1400012c080 cap:8 [0 1 2 3 4 5] 6: 0x1400012c080 cap:8 [0 1 2 3 4 5 6] 7: 0x1400012c080 cap:8 [0 1 2 3 4 5 6 7] 8: 0x1400013c000 cap:16 [0 1 2 3 4 5 6 7 8] 9: 0x1400013c000 cap:16 [0 1 2 3 4 5 6 7 8 9] */ }

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array/append.go~ 0 → 100644

Ignore Space Show notes View array/array.go 0 → 100644
package main import "fmt" func main() { var a[3]int // 要素の値を省略したらゼロ値 fmt.Printf("a: %+v\n", a) // [0, 0, 0] b := [3]int{1, 2, 3} fmt.Printf("b: %+v\n", b) // [1, 2, 3] c := [3]int{1, 2} fmt.Printf("c: %+v\n", c) // [1, 2, 0] d := [3]int{2: 2} fmt.Printf("d: %+v\n", d) // [0, 0, 2] e := [3]int{0:1, 1: 2} fmt.Printf("e: %+v\n", e) // [1, 2, 0] // 要素が比較可能であればその配列型も比較可能 fmt.Printf("a==b: %v\n", a == b) // false fmt.Printf("c==e: %v\n", c == e) // true // f := [4]int{} // fmt.Printf("a==f: %v\n", a == f) // compile error: [3]int == [4]int hoge(a) fmt.Printf("a: %+v\n", a) // [0, 0, 0] // 値渡しなので安全だが性能的に非効率なことがある } func hoge(arg [3]int) { arg[0] = 4 fmt.Printf("%+v\n", arg) // [4, 0, 0] }

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array/array.go 0 → 100644

Ignore Space Show notes View array/slice.go 0 → 100644
package main import "fmt" func main() { s := []string{0:"", 1:"Jan", 2:"Feb", 3:"Mar", 4:"Apr", 5:"May", 6:"Jun", 7:"Jul", 8:"Aug", 9:"Sep", 10:"Oct", 11:"Nov", 12:"Dec"} fmt.Printf("%d\n", len(s)) // 13(0-12) fmt.Printf("%+v\n", s[2:4]) // [Feb Mar] fmt.Printf("%d\n", len(s[2:4])) // 2 fmt.Printf("%d\n", cap(s[2:4])) // 11(2-12) fmt.Printf("%+v\n", s[2:7]) // [Feb Mar Apr May Jun] fmt.Printf("%d\n", len(s[2:7])) // 5 fmt.Printf("%d\n", cap(s[2:7])) // 11(2-12) fmt.Printf("%+v\n", s[:]) // [ Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec] }

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array/slice.go 0 → 100644

Ignore Space Show notes View hello.go
package main import "fmt" func main() { fmt.Println("Hello, World") } package main import "fmt" func main() { fmt.Println("Hello, World") }

Ignore Space Show notes View slice.go 0 → 100644
package main import "fmt" func main() { fmt.Println("Hello, World") }

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