javascript.info | javascript.info 翻译 - javascript

Today I have tried to multiply large numbers using javascript BigInt, I noticed It is producing the wrong result. I tried to find the max size of the BigInt but the websites I have checked not mentioned about the max size of BigInt. Instead, the documentation says BigInt can have arbitrary length.

I have a div (which holds a Zoom iFrame) which I would like to move around the screen. However... on occasion if the user is being jerky with the mouse, it sticks to the pointer and the only way you can fix that is by refreshing the page.

Is that something anyone else has experienced and how did you solve it?

I would imagine its something to do with my Javascript portion and how I am listening for some events.

EDIT: Wanted to add that the below code was basically adjusted for Vue from this article: https://javascript.info/mouse-drag-and-drop

Thanks in advance!

HTML:

I am trying to communicate with cross-origin resources using postMessage(), but am unable to get it to work properly. I have reviewed dozens of other similar questions, but am still stuck.

(https://developer.mozilla.org/en-US/docs/Web/API/Window/postMessage, https://javascript.info/cross-window-communication, How can I do cross-domain postMessage?, etc.)

I have this working on the same origin, but when I move to a different origin, I get a standard corss-origin error.

Uncaught DOMException: Blocked a frame with origin ... from accessing a cross-origin frame.

I call postMessage() twice. Once on page load using the wildcard - which is working. And once using a delcared origin - which is what I need, but can't get to work.

Parent:

This code is from https://javascript.info/object-copy

I'm new to React. I have an </code>. Before it is destroyed or removed I want to call some clean-up code. But I'm not sure how to call that method before destroy. Here is my code:</p> <p><strong>App.js</strong></p> <pre><code>import React, { Component } from "react"; import "./App.css"; export default class App extends Component { lang = "de-DE"; myMethod =()=> { var in_dom = document.body.contains("the_iframe"); var observer = new MutationObserver(function(mutations) { if (document.body.contains("the_iframe")) { if (!in_dom) { console.log("element inserted"); } in_dom = true; } else if (in_dom) { in_dom = false; console.log("element removed"); } }); observer.observe(document.body, {childList: true, subtree: true}); } render() { ... return ( <div className="App"> <header className="App-header"> <span className="App-link"> Change Language </span> <span className="App-link"> Logout </span> </header> <div> <iframe id="the_iframe" width="95%" height="200px" scrolling="no" beforeunload="myMethod()" > ); } }

I took help from here: DOM event when element is removed

Some information I took from here also: DOMContentLoaded, load, beforeunload, unload

Hey, I've been playing this game called "Twilio Quest" for the past week.
I just wanted to learn JavaScript, and I think it looked kinda neat.
The challenges served has been up and down in difficulty. But I've always managed to get around, until now.
Been reading through: JavaScript.info - Classes, MDN - Classes, JavaScript.info - Object literal notation and MDN - Object Initialization I tried alot of aproaches. But I really can't seem to get a hang of this challenge.
Any help would be really appreciated. I just want to learn. Thanks in advance.
Heres what I'm trying to do:

I want to add a side effect every when an array being pushed. For example, I want to add console.log:

Here is a script that I am working on:

I am attemping to create a chess game. I have created 64 divs for the chessboard with the function chessSquares. When I created these I pushed the elements into an array called array which consists of the 64 divs that I created and appended to the chessboard.

The next two functions is the yCoord and xCoord. With these two functions I created div elements with the coordinates for the chessboard and appended to the chessSquares. These elements are the outer elements on the left and top side of the chessboard which display coordinates.

With the following function otherCoord I am trying to make an evaluation where if the id numbers of the elements in array do not match the ID numbers in the array of arrayXYCoord then to push the elements into the array of arrayInnerCoord.

After I do this I will be using a function to assign ID's to the other squares of the chessboard followed by coordinates which can be toggled on and off.

I have tried various ways of doing this such as running two loops at a time and it ends up pushing the id's multiple times into an array and it just seemed really messy. I am looking for a clean way to do this with a simple comparison.

If possible, I would like to use a method from javascript.info/array-methods. Thank you