How to Use Regular Expressions in Go with regexp

Use the regexp package to compile patterns and match strings. Compile the pattern with regexp.MustCompile or regexp.Compile, then use methods like MatchString to test for a match or FindAllString to extract substrings.

package main

import (
	"fmt"
	"regexp"
)

func main() {
	// Compile the regex pattern
	pattern := regexp.MustCompile(`\d+`)

	// Test if the string matches
	if pattern.MatchString("abc123def") {
		fmt.Println("Match found")
	}

	// Find all matches
	matches := pattern.FindAllString("abc123def456", -1)
	fmt.Println(matches) // Output: [123 456]
}

Regular expressions are a powerful way to search for specific patterns inside text, like finding all phone numbers or email addresses in a document. In Go, you first define your pattern as a string and then use the regexp library to check if your text fits that pattern. Think of it like a digital sieve that only lets through the text shapes you are looking for.