javascript

At the beginning, the value of positive is NaN, then, after positive, bad or neutral is added, NaN changes the value: import ... neutral + bad))*100)}</p> </div> </div> ) } export default App;

console.log( null == null, undefined == undefined, NaN == NaN ); // true, true, false Why?

I'm studying js, and the question is ripe: does const differ from var and let in terms of performance and memory occupied by variables? The question may seem silly, but I didn't find any information on it.

I have functions for working with a simple slider, I want to make it infinitely rewind, via setTimeout, but I don't know how ... < 0){ num= image.length-1; } slider.src=image[num]; } setTimeout('next()',2000);

As far as I understand, it's the same thing. But I don't understand why the callback function is called like this. To whom does it return and what does it return? Is there a difference between first-order functions and callback functions?

The animation should only work when you scroll to it. And it doesn't work at all. .box { width: 100px; height: 1 ... ow.min.js"></script> <script> new WOW().init(); </script> </body> </html>

There is an Iframe <iframe src="" name="iframe1" id='iframe1'> </iframe> How can I use java script to set src to ... getElementById('iframe1').contentWindow="1.html"; } - <div onClick="IFrame1()" class='Menu3'> 1 страница </div>

There is a Token file with the request export default async function Token(email, password) { if (!res.ok) { throw new ... ace. login(email, password) .then(() => { history.push('/home'); }); Any help would be appreciated.

I'm doing a site search, but ran into a problem when I hang the input 2 events onChange and onKeyPress, then onChange just re ... rderRadius: "5px"}} value={value.search} onChange={onChange} onKeyPress={onKeyPress} placeholder="Поиск"/> </form>)

Code: var canvas = document.getElementById('canvas'); var canavs.onmousedown = onmd(); var canavs.onmousemove = onmm(); var ... error in the line - var canavs.onmousedown = onmd();. I commented out that line, and he swore at the next one. How to fix it?

The lexical environment is clear, but how to understand closures in JS. What function it performs. You can explain it in simp ... 'Peter'; return function displayName() { console.log(name); }; } let peter = person(); peter(); // 'Peter'

I just asked you a question, I probably did not express myself correctly, or I was not correctly understood. You need to make ... s, in the variable html we have html code of the site page where the request was made. The same should be done on javascript

Good evening I'm writing a small blog engine And I need to make a simple Wysiwyg editor I don't want to use ready-made engine ... ross-browser manual? As an example, you need something like this locanic http://imperavi.com/redactor/ noo paid and on jquery

What libraries are there for viewing powerpoint presentations on your site through an iframe, for example? With the preservation of navigation and links.

I tried to close the browser window using the javascript code page windows.close(). But this command does not work. How can I close the browser window?

I know how to get the value of the selected element. The problem is with which event to catch the selection of the element. I ... ed. If you use change(), then on the contrary, the first element can not be selected in any way. Are there any other options?

Why doesn't the calculator work ? "use strict"; function CalcNumbers(result){ document.getElementById("input").i ... </div> </div> </div> <script src="calc.js"> </script> </body> </html>

Gentlemen, I once again ask a not very smart question. But I searched, and did not find any clear solution. I have an exampl ... () { // вот здесь я хотел бы показать модальный диалог программно } </script> </body> </html>

Please tell me how in Twitter Bootstrap to make the drop-down menu drop down not when you click, but when you hover over the items? Must be done for the element dropdowns.

Help with the implementation of data transfer to the modal window. There is a template container that dynamically receives da ... contents of the container and the modal window. Help me correctly implement data transfer. P.S. I write in pure JavaScript.