#javascript

#javascript

Yes, the shopping crawler has to consume shopping structured data incredibly fast so it has up-to-date pricing, inventory, availability and so forth for the Google Shopping Graph. Because of the speed and quanity of feeds it needs to consume over-and-over again, it does not have time to wait for JavaScript to dynamically generated the structured data.

Step 2: Initialize Canvas and Constants Set up the canvas context and define the physical parameters of your cradle: const canvas = document.getElementById('canvas'); const ctx = canvas.getContext('2d'); const numBalls = 5; // Number of balls in cradle const ballRadius = 20; // Radius of each ball const stringLength = 150; // Length of pendulum string const frameY = 50; // Y position of top frame const spacing = ballRadius * 2 + 2; // Space between balls const centerX = canvas.width / 2; // Center of canvas let balls = []; let dragging = null; // Track which ball is being dragged

Autocomplete seems like one of the easiest features to build. You take the user's input, loop through your list of options, and filter anything that starts with the same prefix: const matches = words.filter(w => w.startsWith(prefix)); And that works for small lists of text. But once your dataset gets large, or your completions come from structured text (like user.address.city or $gte), simple loops start to fall short.

When promises were introduced natively in JavaScript, it was definitely a game-changer. In a lot of projects, the usage of callbacks was replaced by promises for running asynchronous tasks, and promises became the main alternative to it. Promises resemble callbacks in some ways, but with an easier-to-follow syntax and a better understanding of the code.

That gives us the following useful features: We can start a JavaScript console from a shell. We can run files with JavaScript code from a shell. That is useful for automatically testing if our code is correct - a topic that we'll explore in a future chapter. We can write web servers in Node.js - which is another topic that we'll explore in the future. Node.js lets us install shell commands that help with web development.