Go Regex.md

First import the regexp package

import regexp

Matching

match, _ := regexp.MatchString("[a-zA-Z0-9]+", input)

match will be true if the pattern matches. To return the first match as string use

matchstr := regexp.FindString("([a-zA-Z0-9]+)", input)

To return all matches:

matches := regexp.FindAllString("([a-zA-Z0-9]+)", input)

Matching Methods

There are different matching methods

Method	Description	Signature
Match	Test a string for matching a byte slice	func Match(pattern string, b []byte) (matched bool, err error)
MatchString	Test a string for match another string	func MatchString(pattern string, s string) (matched bool, err error)
Find FindIndex FindSubmatch FindSubmatchIndex	Find first byte slices match and return it	func (re *Regexp) Find(b []byte) []byte func (re *Regexp) FindIndex(b []byte) (loc []int) func (re *Regexp) FindSubmatch(b []byte) [][]byte func (re *Regexp) FindSubmatchIndex(b []byte) []int
FindString FindStringIndex FindStringSubmatch FindStringSubmatchIndex	Find first string match and return it	func (re *Regexp) FindString(s string) string func (re *Regexp) FindStringIndex(s string) (loc []int) func (re *Regexp) FindStringSubmatch(s string) []string func (re *Regexp) FindStringSubmatchIndex(s string) []int
FindAll FindAllIndex FindAllString FindAllStringIndex FindAllStringSubmatch FindAllStringSubmatchIndex	Like the Find/FindString methods, just returning all matches	Like the Find/FindString methods, just returning arrays of matches

Replacing

To replace text use ReplaceAll or ReplaceAllString

func (re *Regexp) ReplaceAll(src, repl []byte) []byte
func (re *Regexp) ReplaceAllString(src, repl string) string

e.g.

result := regexp.Compile("\s+").ReplaceAllString(input, " ")

to collapse all whitespaces

Precompiled expressions

Create expression with

r, _ := regexp.Compile("[a-zA-Z0-9]+")

and use it in method form

r.MatchString(input)