Code Explainers

Code explainers tagged #formatting

typescript 
export function formatDuration(ms: number): string {
  if (!Number.isFinite(ms) || ms < 0) {
    return "00:00";
  }

Formatting milliseconds as a clock string

formatting integer-math guard-clause
Beginner 4 steps
javascript 
class DownloadTracker {
  constructor(totalBytes, { windowMs = 3000 } = {}) {
    this.totalBytes = totalBytes;
    this.windowMs = windowMs;

Estimating download speed with a sliding window

sliding-window getters rate-calculation
Intermediate 7 steps
typescript 
export interface FormatBytesOptions {
  decimals?: number;
  binary?: boolean;
}

Formatting byte counts into human-readable sizes

formatting logarithms default-parameters
Intermediate 8 steps
php 
<?php
 
function timeAgo(DateTimeInterface $past, ?DateTimeInterface $now = null): string
{

Building a timeAgo helper in PHP

datetime formatting pluralization
Beginner 6 steps
python 
from datetime import datetime, timezone
 
_INTERVALS = (
    ("year", 60 * 60 * 24 * 365),

Building a human-friendly time_ago helper

datetime timezones formatting
Intermediate 5 steps
php 
<?php
 
namespace App\Services;
 

Building a valid iCalendar feed in PHP in Laravel

ical serialization formatting
Intermediate 8 steps
rust 
pub fn format_size(bytes: u64) -> String {
    const UNITS: [&str; 7] = ["B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB"];
 
    if bytes < 1024 {

Formatting byte counts as human-readable sizes

bit-manipulation formatting unit-conversion
Intermediate 5 steps
typescript 
type CurrencyFormatOptions = {
  locale?: string;
  currency: string;
  showDecimals?: boolean;

Caching Intl.NumberFormat for currency

memoization internationalization caching
Intermediate 9 steps
javascript 
const UNITS = ['B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB'];
 
export function formatBytes(bytes, { decimals = 1, binary = false } = {}) {
  if (!Number.isFinite(bytes)) {

Formatting byte counts into human units

logarithms formatting default-parameters
Intermediate 8 steps
rust 
use std::fmt;
 
#[derive(Clone, Copy, PartialEq, Eq)]
pub struct Money {

Formatting money with Rust's Display trait

trait-implementation integer-arithmetic enums
Intermediate 10 steps
ruby 
require "time"
require "tzinfo"
 
module TimeConverter

Converting timestamps across time zones with TZInfo

timezones iso8601 parsing
Intermediate 8 steps
java 
import java.time.Instant;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;

Converting timestamps across time zones in Java

date-time time-zones instant
Intermediate 6 steps
ruby 
module DurationFormatter
  UNITS = [
    ['week', 604_800],
    ['day', 86_400],

Turning seconds into human-readable durations in Ruby

greedy-decomposition modular-arithmetic formatting
Intermediate 7 steps
go 
package geometry
 
import "fmt"
 

Implementing fmt.Stringer in Go

interfaces stringer composition
Beginner 5 steps