Skip to content

常用函数

sort

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
package main

import (
    "fmt"
    "sort"
)

func main() {

    strs := []string{"c", "a", "b"}
    sort.Strings(strs)
    fmt.Println("Strings:", strs)

    ints := []int{7, 2, 4}
    sort.Ints(ints)
    fmt.Println("Ints:   ", ints)

    s := sort.IntsAreSorted(ints)
    fmt.Println("Sorted: ", s)
}

输出: 

1
2
3
Strings: [a b c]
Ints:    [2 4 7]
Sorted:  true

Sorting by Functions

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
package main

import (
    "fmt"
    "sort"
)

type byLength []string

func (s byLength) Len() int {
    return len(s)
}
func (s byLength) Swap(i, j int) {
    s[i], s[j] = s[j], s[i]
}
func (s byLength) Less(i, j int) bool {
    return len(s[i]) < len(s[j])
}

func main() {
    fruits := []string{"peach", "banana", "kiwi"}
    sort.Sort(byLength(fruits))
    fmt.Println(fruits)
}

输出: 

1
[kiwi peach banana]

random

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
package main

import (
    "fmt"
    "math/rand"
    "time"
)

func main() {
    fmt.Print(rand.Intn(100), ",")
    fmt.Print(rand.Intn(100))
    fmt.Println()

    fmt.Println(rand.Float64())

    fmt.Print((rand.Float64()*5)+5, ",")
    fmt.Print((rand.Float64() * 5) + 5)
    fmt.Println()

    s1 := rand.NewSource(time.Now().UnixNano())
    r1 := rand.New(s1)

    fmt.Print(r1.Intn(100), ",")
    fmt.Print(r1.Intn(100))
    fmt.Println()

    s2 := rand.NewSource(42)
    r2 := rand.New(s2)
    fmt.Print(r2.Intn(100), ",")
    fmt.Print(r2.Intn(100))
    fmt.Println()
    s3 := rand.NewSource(42)
    r3 := rand.New(s3)
    fmt.Print(r3.Intn(100), ",")
    fmt.Println(r3.Intn(100))
}

输出: 

1
2
3
4
5
6
81,87
0.6645600532184904
7.1885709359349015,7.123187485356329
76,32
5,87
5,87

URL Parsing

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
package main

import (
    "fmt"
    "net"
    "net/url"
)

func main() {
    s := "postgres://user:pass@host.com:5432/path?k=v#f"

    u, err := url.Parse(s)
    if err != nil {
        panic(err)
    }

    fmt.Println(u.Scheme)

    fmt.Println(u.User)
    fmt.Println(u.User.Username())
    p, _ := u.User.Password()
    fmt.Println(p)

    fmt.Println(u.Host)
    host, port, _ := net.SplitHostPort(u.Host)
    fmt.Println(host)
    fmt.Println(port)

    fmt.Println(u.Path)
    fmt.Println(u.Fragment)

    fmt.Println(u.RawQuery)
    m, _ := url.ParseQuery(u.RawQuery)
    fmt.Println(m)
    fmt.Println(m["k"][0])
}

输出: 

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
postgres
user:pass
user
pass
host.com:5432
host.com
5432
/path
f
k=v
map[k:[v]]
v

SHA1 Hashes

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
package main

import (
    "crypto/sha1"
    "fmt"
)

func main() {
    s := "sha1 this string"

    h := sha1.New()

    h.Write([]byte(s))

    bs := h.Sum(nil)

    fmt.Println(s)
    fmt.Printf("%x\n", bs)
}

输出: 

1
2
sha1 this string
cf23df2207d99a74fbe169e3eba035e633b65d94

Base64 Encoding

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
package main

import (
    b64 "encoding/base64"
    "fmt"
)

func main() {

    data := "abc123!?$*&()'-=@~"

    sEnc := b64.StdEncoding.EncodeToString([]byte(data))
    fmt.Println(sEnc)

    sDec, _ := b64.StdEncoding.DecodeString(sEnc)
    fmt.Println(string(sDec))
    fmt.Println()

    uEnc := b64.URLEncoding.EncodeToString([]byte(data))
    fmt.Println(uEnc)
    uDec, _ := b64.URLEncoding.DecodeString(uEnc)
    fmt.Println(string(uDec))
}

输出: 

1
2
3
4
5
YWJjMTIzIT8kKiYoKSctPUB+
abc123!?$*&()'-=@~

YWJjMTIzIT8kKiYoKSctPUB-
abc123!?$*&()'-=@~