Beginner code explainers

java

public class SortedListMerger {
 
    public static int[] merge(int[] a, int[] b) {
        int[] result = new int[a.length + b.length];

Merging two sorted arrays in Java

two-pointers merging arrays

Beginner 6 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

php

<?php
 
namespace App\Http\Middleware;

Enforcing a JSON Accept header in Laravel

middleware content-negotiation http-headers

Beginner 5 steps

go

package handlers
 
import (
	"net/http"

Rendering HTML pages with Gin handlers

http-handlers templating error-handling

Beginner 8 steps

go

package handlers
 
import (
	"net/http"

Reading path parameters in Gin

routing path-parameters wildcards

Beginner 7 steps

python

from collections import Counter
 
 
def word_frequencies(text):

Counting things with collections.Counter

counting multiset data-structures

Beginner 8 steps

go

package geometry
 
import "fmt"

Implementing fmt.Stringer in Go

interfaces stringer composition

Beginner 5 steps