Advertisements In the React document, it mentions that when rendering a list without keys, React will mutate every child instead of realizing it can keep the items subtrees intact. This inefficiency can be a problem. I am wondering how I can verify this kind of impact, for example this is the demo I’m writing now:… Read More Is it possible to validate the performance impact when React render list with or without key

Advertisements Since in Java, generics usually operate on Object under the hood, I was curious if emplacing such values incurs more overhead than placing an already existing object. Consider having a Map<String, Object> that can contain arbitrary meta information. You want to put a flag kinda entry there – if it is present, the flag… Read More When a boolean or int are placed in a java Map that contains Objects, does emplacing them actually create a new Object?

Advertisements I am having a problem in Python efficiently getting the next row in a dataframe that has a matching ID number. An example of what I’m working with looks like this: ids = [1,2,3,4,5] customer_ids = [3,7,5,7,3] dates = [‘2020-04-03’, ‘2020-04-07′,’2020-04-14′,’2020-05-02′,’2020-05-06’] df = pd.DataFrame({ ‘ID’: ids, ‘Customer_ID’: customer_ids, ‘Date’: dates}) What I want for… Read More Finding the next row in a Pandas dataframe with matching user ID number Python

Advertisements I have this simple code (the purpose of this code is irrelevant) const filter = function (object, subject, match) { const result = []; let index = 0; for (let i = 0; i < object.length; i++) { let existingIndex = -1; for (let j = index; j < subject.length; j++) { if (match(object[i],… Read More JavaScript loop with anonymous function performance

Advertisements How do I remove the event listener, so the alert box will not be popped up anymore after Remove Listener to prevent it from triggering pop_up button is clicked? document.querySelector(‘#hihi-toggle’).addEventListener(‘click’, e => { alert(“I am Jim”) }); function remove_event_listener_button() { //document.querySelector(‘#hihi-toggle’).removeEventListener() } <button id=”hihi-toggle” data-enabled=”false”>Alert Box </button> <button onclick=”remove_event_listener_button()”>Remove Listener to prevent it from… Read More Remove Event Listener of Button

Advertisements The code snippet provided will Pop Up Alert when Backspace and Delete Key is Pressed on Keyboard with the cursor clicked on the textbox. However, now I want to implement it in my codepen demo here, but I am unsure on how to do it. I want the alert box to pop up only… Read More Trigger Delete on Keyboard

Advertisements console.clear(); function my_Func() { //I have a lot of code in this Function Which Is Confusing document.querySelector(‘#return-toggle’).addEventListener(‘click’, e => { return_status = “yes”; alert(“Hello!!!!”) }); } my_Func() my_Func() my_Func() my_Func() <button id=”return-toggle”>Display Alert </button> Basically, I used query selector to trigger id of button. My code requires some function to be called multiple times… Read More addEventListener to a Button ID

Advertisements let paths = document.querySelectorAll(‘path’); // paths is an html collection of all paths; // attach event listeners to each path; for (let i=0; i<paths.length; i++) { paths[i].addEventListener(‘click’, event => alert(event.target.dataset.key)); } function Path_1(){} function Path_2(){} <button onclick=”Path_1()”>Path_1</button> <button onclick=”Path_2()”>Path_2</button> <svg xmlns=”http://www.w3.org/2000/svg&#8221; xmlns:xlink=”http://www.w3.org/1999/xlink&#8221; version=”1.1″ width=”800pt” height=”600pt” viewBox=”0 0 800 600 ” id=”svg1″> <g enable-background=”new”> <path… Read More Trigger An Event Listener