Snagging Yesterday’s Date in JavaScript: A Time-Traveler’s Guide

Hey there, fellow time travelers! Ever found yourself coding up a storm and suddenly needing to grab yesterday’s date in JavaScript? It’s like you’re working on this cool feature, and boom, you need to take a tiny step back in time. Well, don’t sweat it, ’cause I’m about to walk you through the ins and outs of getting that elusive yesterday’s date in plain ol’ JavaScript and across a couple of popular frameworks. Let’s dive in!

Vanilla JavaScript – No Framework, No Problem

Sometimes, you just gotta appreciate the simple things in life, like vanilla JavaScript. No extra fluff, just pure, straightforward code. Here’s how you can get yesterday’s date with the language’s built-in Date object:

const today = new Date();
const yesterday = new Date(today);

yesterday.setDate(yesterday.getDate() - 1);

console.log(yesterday); // Logs yesterday's date

In this little snippet, we first create a Date object for today. Then, we clone it—’cause we’re respectful of the space-time continuum—and adjust the date by subtracting one day. Voilà, you’ve got yesterday!

React – A Component for the Past

Ah, React. It’s like the cozy coffee shop of JavaScript frameworks where you can just sit down and start creating beautiful UI components. Let’s say you want to display yesterday’s date in a React component. Here’s how you’d do it:

import React from 'react';

const YesterdayDate = () => {
  const today = new Date();
  const yesterday = new Date(today);

  yesterday.setDate(yesterday.getDate() - 1);

  return (
    <div>
      <p>Yesterday was: {yesterday.toDateString()}</p>
    </div>
  );
};

export default YesterdayDate;

In this component, YesterdayDate, we’re doing the same date manipulation as before, but this time we’re wrapping it in React’s embrace and displaying it with JSX. Neat, right?

Angular – Going Back in Time, the TypeScript Way

Angular and TypeScript go together like peanut butter and jelly. Angular’s structure and TypeScript’s type safety can make your code more robust. Here’s a quick example of a service in Angular that gets you yesterday’s date:

import { Injectable } from '@angular/core';

@Injectable({
  providedIn: 'root'
})
export class DateService {
  getYesterday(): Date {
    const today = new Date();
    const yesterday = new Date(today);

    yesterday.setDate(yesterday.getDate() - 1);

    return yesterday;
  }
}

This DateService can be injected into any component that needs to know what day it was yesterday. Angular’s dependency injection system makes it super easy to share functionality like this across your app.

Vue.js – Reactive Time Travel

Vue.js, the progressive framework that’s all about making the developer’s life easier. Let’s take a peek at how you’d get yesterday’s date in a Vue instance:

<template>
  <div>
    <p>Yesterday was: {{ yesterday }}</p>
  </div>
</template>

<script>
export default {
  data() {
    return {
      yesterday: this.getYesterdayDate()
    };
  },
  methods: {
    getYesterdayDate() {
      const today = new Date();
      const yesterday = new Date(today);

      yesterday.setDate(yesterday.getDate() - 1);

      return yesterday.toDateString();
    }
  }
};
</script>

In this Vue example, we’ve got a data property yesterday that’s initialized by calling the getYesterdayDate method. This method does our usual time trickery, and the result is displayed reactively in the template. Vue’s reactivity system will ensure that if yesterday changes, the DOM will update automatically.

Alright, fellow devs, that wraps up the first half of our journey through JavaScript dates. We’ve covered the basics and how to work with yesterday’s date in vanilla JS and a few of the most popular frameworks. Stay tuned for the second half, where we’ll dive even deeper and explore more scenarios and solutions for handling dates in the wild world of web development.

Svelte – The New Kid on the Block

Svelte is the shiny new framework that’s been turning heads with its compile-time magic. Instead of doing all the heavy lifting in the browser, Svelte shifts that work to compile time, resulting in uber-efficient code. Here’s how you’d get yesterday’s date in a Svelte component:

<script>
  let today = new Date();
  let yesterday = new Date(today.setDate(today.getDate() - 1));
</script>

<p>Yesterday was: {yesterday.toDateString()}</p>

In this Svelte snippet, we’re declaring our date variables right in the script tag, and then we simply output yesterday in the markup. Svelte takes care of the reactivity for us, so if today changes, yesterday will update accordingly.

Node.js – Server-Side Time Warp

Sometimes you need to get your hands on yesterday’s date on the server side. Node.js, our trusty JavaScript runtime, makes this a breeze. Here’s how you’d do it in a Node.js script:

const today = new Date();
const yesterday = new Date(today);

yesterday.setDate(yesterday.getDate() - 1);

console.log(`Yesterday's date was: ${yesterday.toDateString()}`);

This code would look pretty familiar because, hey, Node.js is JavaScript! But remember, since this is server-side, you’re not limited to the client’s time zone. You could use libraries like Moment.js or date-fns to handle time zones and other complex date manipulations.

Libraries to the Rescue – Moment.js and date-fns

Speaking of libraries, let’s not forget our helpful third-party friends that make date handling a walk in the park.

Moment.js

Moment.js has been a go-to library for date manipulation in JavaScript for years. Here’s how you’d get yesterday’s date with Moment.js:

const moment = require('moment');

const yesterday = moment().subtract(1, 'days');

console.log(yesterday.format('YYYY-MM-DD')); // Formats the date to a string

Moment.js makes it super easy to subtract days, format dates, and much more. However, it’s worth noting that Moment.js is considered a legacy project, and the team now recommends using other modern alternatives.

date-fns

date-fns is a modern JavaScript date utility library that provides the most comprehensive, yet simple and consistent toolset for manipulating JavaScript dates in a browser & Node.js.

const { subDays } = require('date-fns');

const today = new Date();
const yesterday = subDays(today, 1);

console.log(yesterday.toISOString()); // Outputs the ISO string of yesterday's date

With date-fns, you get a modular library where you can pick and choose only the functions you need, potentially resulting in smaller bundle sizes.

Wrapping Up – Time Travel Completed

There you have it, fellow devs—your comprehensive guide to getting yesterday’s date in JavaScript, whether you’re working with vanilla JS, React, Angular, Vue, Svelte, Node.js, or even utilizing libraries like Moment.js and date-fns.

Remember, handling dates can sometimes be trickier than it seems, especially when time zones and daylight saving times come into play. Libraries can help you navigate these waters, but always test your date manipulations thoroughly.

Now go forth and code with the confidence of a seasoned time traveler, capable of hopping back to yesterday with ease! Whether it’s for generating reports, setting default form values, or just reminiscing about the good ol’ days of coding, you’re all set to handle dates like a pro. Keep on coding, and may your functions always return true!