The golang regular regexp package uses -06- other usages (special character conversion, finding the regular common prefix, switching greedy mode, querying the number of regular groups, querying the na

1. QuoteMeta() function （ Special character conversion ）

Convert special characters of regular expressions .

grammar

func QuoteMeta(s string) string

Complete example

package main

import (
	"fmt"
	"regexp"
)

func main() {
    
	pattern := " Xuande .*?"
    myString := regexp.QuoteMeta(pattern)
	fmt.Println(myString)
}

• result

 Xuande \.\*\?

2. LiteralPrefix() Method （ Find the regular common prefix ）

grammar

func (re *Regexp) LiteralPrefix() (prefix string, complete bool)

prefix： Common prefix
complete： If prefix Is the regular expression itself , Then return to true, Otherwise return to false

Complete example

• Code

package main

import (
	"fmt"
	"regexp"
)

func main() {
    
	reg := regexp.MustCompile(`Hello[\w\s]+`)
	fmt.Println(reg.LiteralPrefix())

	reg = regexp.MustCompile(`Hello`)
	fmt.Println(reg.LiteralPrefix())

	reg = regexp.MustCompile(`.*Hello`)
	fmt.Println(reg.LiteralPrefix())
}

• result

Hello false
Hello true
 false

Above

• Results a , Common prefix hello Returned ,false The prefix is not the regular expression string itself
• Result two , Common prefix hello Returned ,true The prefix is the regular expression string itself
• Result three , No common prefix

3. Longest() Method （ Switch greedy mode ）

grammar

func (re *Regexp) Longest()

Complete example

package main

import (
	"fmt"
	"regexp"
)

func main() {
    
	s := `10.10.239.11`
	reg := regexp.MustCompile(".*?\\.")
	fmt.Printf("%s\n", reg.FindString(s))

	reg.Longest() //  Switch greedy mode 
	fmt.Printf("%s\n", reg.FindString(s))
}

• result

10.
10.10.239.

4. NumSubexp() Method （ Query the number of groups in the regular ）

grammar

func (re *Regexp) NumSubexp() int

Complete example

• Code

package main

import (
	"fmt"
	"regexp"
)
func main() {
    
	reg := regexp.MustCompile("(\\d+)\\.(\\d+)")
	n := reg.NumSubexp()
	fmt.Printf(" The number of groups in the regular is ：%d",n)

}

• result

 The number of groups in the regular is ：2

5. Split() Method （ With regular cut ）

grammar

func (re *Regexp) Split(s string, n int) []string

Complete example

• Code

package main

import (
	"fmt"
	"regexp"
)

func main() {
    
	reg := regexp.MustCompile(`\.`)
	myString := "www.xishu.com"
	result := reg.Split(myString, -1)
	fmt.Printf(" result ：%q\n",result )

}

• result

 result ：["www" "xishu" "com"]

6. String() Method （ take *regexp.Regexp In the instance, the regular pattern is string Output ）

grammar

func (re *Regexp) String() string

Complete example

package main

import (
	"fmt"
	"regexp"
)

func main() {
    
	reg := regexp.MustCompile("\\d+$")
	pattern := reg.String()
	fmt.Printf("%s\n", pattern)
}

• result

\d+$

7. SubexpNames() Method （ Returns the regular group name ）

grammar

func (re *Regexp) SubexpNames() []string

Name regular groups ：

(?P<NAME>)

Complete example

package main

import (
	"fmt"
	"regexp"
)
func main() {
    
	reg := regexp.MustCompile("(?P<first>\\d+)\\.(?P<second>\\d+)\\.(?P<third>\\d+)\\.(?P<fourth>\\d+)$")
	namesList := reg.SubexpNames()
	fmt.Printf("%+v\n", namesList)
}

• result

[ first second third fourth]

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https://blog.csdn.net/qq_41629756/article/details/100516635