#regex code explainers

java

@Target({ElementType.FIELD, ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = StrongPasswordValidator.class)
@Documented

Building a custom @StrongPassword validator in Spring

bean-validation annotations regex

Intermediate 7 steps

php

<?php
 
namespace App\Support;

Building a URL slug from any title in PHP

regex transliteration string-processing

Intermediate 8 steps

ruby

class HostnameValidator < ActiveModel::EachValidator
  MAX_LENGTH = 253
  LABEL = /\A(?!-)[a-z0-9-]{1,63}(?<!-)\z/i

Writing a custom hostname validator in Rails

validation custom validator regex

Intermediate 8 steps

java

public final class RegistrationValidator {
 
    private static final Pattern EMAIL = Pattern.compile("^[\\w.+-]+@[\\w-]+\\.[\\w.-]+$");
    private static final Pattern USERNAME = Pattern.compile("^[a-zA-Z0-9_]{3,20}$");

Accumulating validation errors in Java

validation regex error-accumulation

Beginner 9 steps

python

import re
from datetime import datetime
from dataclasses import dataclass

Parsing access logs with named regex groups

regex named-groups dataclasses

Intermediate 6 steps

ruby

module TextAnalysis
  module_function
 
  WORD_PATTERN = /[\p{Alpha}']+/

Building a word-frequency analyzer in Ruby

text processing regex enumerable

Intermediate 8 steps

typescript

type SignupInput = {
  email: string;
  password: string;
  confirmPassword: string;

How a typed signup validator collects errors

form-validation type-safety regex

Intermediate 9 steps