% cat main.go
package main
// https://pkg.go.dev/regexp
// https://pkg.go.dev/regexp/syntax
import (
"fmt"
"regexp"
)
func main() {
input := `
<html>
<head>
<title>study golang</title>
</head>
<body>
<ul>
<li>changyy.org</li>
<li>1234567890</li>
<li>abcdefg</li>
<li>abcdefgABCDEFG</li>
<li>abcdef1234567890gABCDEFG</li>
</ul>
</body>
</html>`
// Style 1: regexp.Match
{
matched, err := regexp.Match(`<[A-Za-z]+>(.*?)</[A-Za-z]+>`, []byte(input))
if err != nil {
fmt.Println("Style 1 - regexp.Match error:", err)
} else {
fmt.Println("Style 1 - regexp.Match: ", matched)
}
}
// Style 2: regexp.Compile + obj.MatchString
// https://pkg.go.dev/regexp#Regexp.MatchString
{
obj, err := regexp.Compile(`<[A-Za-z]+>(.*?)</[A-Za-z]+>`)
if err != nil {
fmt.Println("regexp.Compile error:", err)
} else {
fmt.Println("Style 2 - case 1: ", obj.MatchString(`<title>Hello World</title>`))
fmt.Println("Style 2 - case 2: ", obj.MatchString(input))
}
}
// Style 3: regexp.MustCompile + obj.MatchString
// https://pkg.go.dev/regexp#Regexp.MatchString
{
pattern := `<[A-Za-z]+>(.*?)</[A-Za-z]+>`
obj := regexp.MustCompile(pattern)
fmt.Println("Style 3 - case 1: ", obj.MatchString(`<title>Hello World</title>`))
fmt.Println("Style 3 - case 2: ", obj.MatchString(input))
}
// Style 4: obj.FindString
// https://pkg.go.dev/regexp#Regexp.FindString
{
pattern := `<[A-Za-z]+>(.*?)</[A-Za-z]+>`
obj := regexp.MustCompile(pattern)
fmt.Println("Style 4 - case 1: ", obj.FindString(`<title>Hello World</title>`))
fmt.Println("Style 4 - case 2: ", obj.FindString(input))
}
// Style 5: obj.FindAllString , obj.FindAllStringIndex
// https://pkg.go.dev/regexp#Regexp.FindAllString
// https://pkg.go.dev/regexp#Regexp.FindAllStringIndex
{
pattern := `<[A-Za-z]+>(.*?)</[A-Za-z]+>`
obj := regexp.MustCompile(pattern)
fmt.Println("Style 5 - case 1: ", obj.FindAllString(`<title>Hello World</title>`, -1))
fmt.Println("Style 5 - case 2: ", obj.FindAllString(input, -1))
fmt.Println("Style 5 - case 3: ", obj.FindAllStringIndex(`<title>Hello World</title>`, -1))
fmt.Println("Style 5 - case 4: ", obj.FindAllStringIndex(input, -1))
}
// Style 6: obj.FindStringSubmatch , obj.FindStringSubmatchIndex
// https://pkg.go.dev/regexp#Regexp.FindStringSubmatch
// https://pkg.go.dev/regexp#Regexp.FindStringSubmatchIndex
{
pattern := `<[A-Za-z]+>(.*?)</[A-Za-z]+>`
obj := regexp.MustCompile(pattern)
fmt.Println("Style 6 - case 1: ", obj.FindStringSubmatch(`<title>Hello World</title>`))
fmt.Println("Style 6 - case 2: ", obj.FindStringSubmatch(input))
fmt.Println("Style 6 - case 3: ", obj.FindStringSubmatchIndex(`<title>Hello World</title>`))
fmt.Println("Style 6 - case 4: ", obj.FindStringSubmatchIndex(input))
}
// Style 7: obj.ReplaceAllString
// https://pkg.go.dev/regexp#Regexp.ReplaceAllString
{
pattern := `<[A-Za-z]+>(.*?)</[A-Za-z]+>`
obj := regexp.MustCompile(pattern)
fmt.Println("Style 7 - case 1: ", obj.ReplaceAllString(`<title>Hello World</title>`, "A"))
fmt.Println("Style 7 - case 2: ", obj.ReplaceAllString(input, "B"))
}
// Style 8: obj.Split
// https://pkg.go.dev/regexp#Regexp.Split
{
pattern := `<[A-Za-z]+>(.*?)</[A-Za-z]+>`
obj := regexp.MustCompile(pattern)
fmt.Println("Style 8 - case 1: ", len(obj.Split(`<title>Hello World</title>`, -1)))
fmt.Println("Style 8 - case 2: ", len(obj.Split(input, -1)))
}
// Style 9: obj.Longest()
// https://pkg.go.dev/regexp#Regexp.FindString
// https://pkg.go.dev/regexp#Regexp.Longest
{
pattern := `a(|b)`
obj := regexp.MustCompile(pattern)
fmt.Println("Style 9 - case 1: ", obj.FindString(`abb`))
obj.Longest()
fmt.Println("Style 9 - case 2: ", obj.FindString(`abb`))
}
}
% go run main.go
Style 1 - regexp.Match: true
Style 2 - case 1: true
Style 2 - case 2: true
Style 3 - case 1: true
Style 3 - case 2: true
Style 4 - case 1: <title>Hello World</title>
Style 4 - case 2: <title>study golang</title>
Style 5 - case 1: [<title>Hello World</title>]
Style 5 - case 2: [<title>study golang</title> <li>changyy.org</li> <li>1234567890</li> <li>abcdefg</li> <li>abcdefgABCDEFG</li> <li>abcdef1234567890gABCDEFG</li>]
Style 5 - case 3: [[0 26]]
Style 5 - case 4: [[27 54] [103 123] [136 155] [168 184] [197 220] [233 266]]
Style 6 - case 1: [<title>Hello World</title> Hello World]
Style 6 - case 2: [<title>study golang</title> study golang]
Style 6 - case 3: [0 26 7 18]
Style 6 - case 4: [27 54 34 46]
Style 7 - case 1: A
Style 7 - case 2:
<html>
<head>
B
</head>
<body>
<ul>
B
B
B
B
B
</ul>
</body>
</html>
Style 8 - case 1: 2
Style 8 - case 2: 7
Style 9 - case 1: a
Style 9 - case 2: ab
