I was wondering, with v8, when storing class attributes, is it more performant to use one variable with mixed types or one variable per type? Consider the following snippets (written in TypeScript for making the difference more clear): Afaik both should have advantages or defaults. Using one variable would have the problem that the JS engine might make assumptions on
Tag: performance
React-konva slow drag performance with large number of lines rendered
I have problem with dragging functionality while having large number of rendered lines in React-konva. Currently I am mapping over Array.apply(null, Array(10000)) to render lines horizontally. However, it is very laggy comparing to dragging over an array of only 500 lines for example. I have prepared codesandbox to illustrate this issue: https://codesandbox.io/s/dazzling-hooks-0xc4s?file=/src/App.js (Drag mouse horizontally to see the effect) Any
How can I fix this button
When I click on any button it shows same first button output. How can I fix it. I want it be different when I click on different button it should display same output that button has. I want it to be on my website. Answer Using nextElementSibling:
PerformanceResourceTiming.responseStart and PerformanceResourceTiming.requestStart both are 0 for a status ok http request
I want to measure TTFB (Time to First Byte) for an HTTP request. I’ve hosted a 0KB pdf file on an amazon S3 server, and I’m using the fetch api to get it. Here’s my code: In the chrome developers network tab, I can see the request and all of its timing info: But I can’t access this info in
How can I most easily identify bottlenecks in React render performance?
I’m having an issue with identifying bottlenecks in render performance while working on a JSON viewer. With few elements, it performs well, but at a certain point it becomes annoyingly slow. Checking the profiler, it seems that elements are rendering fast enough, but I’ve noticed a few issues that I’m not sure how to pursue. Overview The app is a
Why sometimes does the img jump in this Blackjack game
In this Blackjack game (https://schaulcode.github.io/blackjack/) written in javaScript sometimes when the cards get dealt the img jumps. it looks like the code gets executed faster the the browser can paint the picture. Interestingly this only happens online, during development when the whole program was locally on my machine this issue didn’t occur. Could anyone explain the reason behind it and
Question about code execution and the nature of javascript blocking/ non blocking
Basically I have something similar to the code below and I’m not entirely sure what order of execution is always going to happen. Right now I suppose it executes in a non blocking fashion, being But I’ve had times that it’s I have no control over when res.on(‘data’) is called because it is a socket event listener and is handled
value of using React.forwardRef vs custom ref prop
I see that React.forwardRef seems to be the sanctioned way of passing a ref to a child functional component, from the react docs: However, what is the advantage of doing this over simply passing a custom prop?: The only advantage I can think of is maybe having a consistent api for refs, but is there any other advantage? Does passing
Proper way to handle many event listeners in javascript
In my website, I have a dynamically growing list, (from a database) that has buttons attached to each item of the list. The button goes to the same javascript function, but each element in the list has a different id, which needs to be included inside the function when it is running. I’m currently using onclick in the html and
PERFORMANCE Accessing a parent using child.parentNode vs getElementById
I want to access the parent of an element. I can access the parent by using child.parentNode but I have the parent id so i can also access it by using getElementById() The question is: which way is better in terms of performance? And why is it better? Answer So, rather than speculating on this, I decided to leverage jsPerf