var ch = 'a'
代表utf8编码的avar ch byte = 'a'
代表ascii码编码的a// 单引号只能创建字符,根据ascii编码
package main
import "fmt"
func main() {
var a = 'a'
fmt.Println(a)
}
// 结果 97
package main
import "fmt"
func main() {
var a = "Wyc"
fmt.Println(a)
}
// 结果 Wyc
package main
import "fmt"
func main() {
json_str := `
{"id": 1, "name": "wWyc"}
`
fmt.Println(json_str)
}
package main
import (
"fmt"
"unicode/utf8"
)
func main() {
name := "Wyc"
//name1 := "Hello World"
//name2 := "test 测试"
fmt.Printf("%v, %d, %d", name, len(name), utf8.RuneCountInString(name))
}
// len 打印出来的是ascii字符的个数
// utf8.RuneCountInString 打印出来的是字符串的长度
package main
import "fmt"
func main() {
name2 := "test 测试"
// 下标遍历 中文打印会打印出乱码
for i := 0; i<len(name2); i++ {
fmt.Printf("%c- %d\n", name2[i], name2[2])
}
// range 遍历 会把所有的打印出来
for _,i := range name2{
fmt.Printf("%c-%d\n", i, i)
}
}
package main
import "fmt"
func main() {
url := "https://"
urlPath := "localhost:8080"
result := url + urlPath
fmt.Println(result)
}
// 修改字符串8080 改成8081
package main
import "fmt"
func main() {
url := "https://"
urlPath := "localhost:8080"
// 字符串拼接
result := url + urlPath
fmt.Println(result)
// 将字符串强制换换成byte
sByte := []byte(result)
fmt.Println(sByte)
// 取出byte最后一个元素
fmt.Println(len(sByte) - 1)
// 取出byte最后一个元素强制赋值
sByte[len(sByte)-1] = '1'
s3 := string(sByte)
fmt.Println(s3)
}
/*
结果
https://localhost:8080
[104 116 116 112 115 58 47 47 108 111 99 97 108 104 111 115 116 58 56 48 56 48]
21
https://localhost:8081
*/
package main
import (
"fmt"
"strings"
)
func main() {
url := "https://"
urlPath := "localhost:8080你好"
// 字符串拼接
result := url + urlPath
// 查找子串
fmt.Println(strings.Contains(result, "8080"))
// 查看任意字符是否包含, 如果包含就为true
fmt.Println(strings.ContainsAny(result, "80 80"))
// 查看是否包含rune类型字符串
fmt.Println(strings.ContainsRune("你好", '测'))
}
/*
结果
true
true
false
*/
package main
import (
"fmt"
"strings"
)
func main() {
s1 := "localhost:8080你好"
s2 := "inf.bigdata.kafka"
s3 := "localhost:8080/v1/app/login"
split_s1 := strings.Split(s1, ":")
split_s2 := strings.SplitN(s3, "/", 2)
split_s3 := strings.SplitAfter(s2, ".")
fmt.Println(split_s1)
fmt.Println(split_s2)
fmt.Println(split_s3)
}
/*
结果
[localhost 8080你好]
[localhost:8080 v1/app/login]
[inf. bigdata. kafka]
*/
package main
import (
"fmt"
"strings"
)
func main() {
s1 := "localhost:8080你好"
fmt.Println(strings.HasPrefix(s1, "lo"))
fmt.Println(strings.HasSuffix(s1, "你好"))
}
package main
import (
"fmt"
"time"
)
func main() {
want := `
[报警触发类型: %s]
[报警名称:%s]
[报警次数: %d]
[报警表达式: %s]
[报警时间: %s]
`
newWant := fmt.Sprintf(want,
"微信支付接口预警",
"支付失败",
4,
`sum(reta(user_pay[1m])) > 100`,
// 2006-01-02 15:04:05 这个是固定的不可修改,修改之后时间获取错误
time.Unix(time.Now().Unix(), 0).Format("2006-01-02 15:04:05"),
)
fmt.Println(newWant)
/*
fmt.Sprintf
*/
}
/*
结果
[报警触发类型: 微信支付接口预警]
[报警名称:支付失败]
[报警次数: 4]
[报警表达式: sum(reta(user_pay[1m])) > 100]
[报警时间: 2023-02-24 211:2411:2411]
*/
package main
import (
"fmt"
"strings"
)
func main() {
str := "@@@@ABCDTESTHELLOWORLD@WYC@"
fmt.Println(strings.Trim(str, "@")) // 去除两边符号
fmt.Println(strings.TrimRight(str, "@"))
fmt.Println(strings.TrimLeft(str, "@"))
fmt.Println(strings.ToLower(str)) // 变小写
fmt.Println(strings.ToUpper(str)) // 变大写
fmt.Println(strings.TrimPrefix("tetetete", "te")) // 去除指定字符
}
package main
import (
"fmt"
"strings"
)
func main() {
base := "https://www.baidu.com/v1?"
args := strings.Join([]string{"name=Wyc", "age=20"}, "&")
arg := base+args
fmt.Println(arg)
}
/*
结果
https://www.baidu.com/v1?name=Wyc&age=20
*/
package main
import (
"fmt"
"strings"
)
func main() {
ss := []string{
"A",
"B",
"C",
"D",
}
var b strings.Builder
for _,s:=range ss{
b.WriteString(s)
}
fmt.Println(b.String())
}