I was trying to comprehend the use of Promise in Javascript for which Google search lead me to this article The author of post points out this Promises (like callbacks) allow us to wait on certain code to finish execution prior to running the next bit of code. Which for some reason sounded like this to me (an…
Tag: javascript
Copy Selected Checkbox Value From One Checkbox To Another Immediately Using JQUERY
I’m relatively new to Jquery and have been struggling with this problem for the last day or so. I am trying to do something seemingly simple, but I can’t quite work it out. I have two identical checkboxes with many entries and multiple choices can be selected by the end user in either checkbox. If…
How can I properly record a MediaStream?
The situation I need to do the following: Get the video from a <video> and play inside a <canvas> Record the stream from the canvas as a Blob That’s it. The first part is okay. For the second part, I managed to record a Blob. The problem is that the Blob is empty. The view The code The resul…
Making my own ForEach() javascript – element is not defined
I am making my own implementation of forEach in javascript, with the sole purpose of understanding the language better. To be more specific the temporary goal is to understand callbacks better. This is how far I got until I got stuck. I get the following error when running in node: I suspect it is because whe…
Sum all data in array of objects into new array of objects
I have an array of objects that looks like this: and I want to sum each element in the array to produce an array like this: I have used a map and reduce function but I was able to only sum an individual element like so: At the moment this produces a single value which is not what I want
How to Create a online based HTML Source code editor like the one in W3Schools.com using jQuery? [closed]
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. We don’t allow questions seeking recommendations for books, tools, software libraries, and more. You can edit the question so it can be answered with facts and citations. Closed 2 years ago. Improve this ques…
JS: Resizing canvas + redrawing elements on canvas
My question: What’s the best way to resize the canvas with all its drawn elements? I have 2 examples where I tried to archieve this. The first one works, but lacks functionality because if I would add many more elements to be drawn it would get very messy. In my second example I tried to put everything …
Calculate the volume of cylinder with JavaScript using prototype
I’m a JavaScript noob and beginner so don’t get too hard on me. I need to calculate the volume of a cylinder using a constructor function and prototype. I’ve got a form with two inputs which I’ll be getting the values from to do the calculation with. I have to create a new instance whe…
How to deal with a ref within a loop?
Below is my parent component with multiple inputs from a loop. How can I choose one input to focus? Do I have to create a dynamic ref in this case? Answer You can use callback refs to generate and store the dynamic ref of each input in an array. Now you can refer to them using the index of the
How can I use moment.js to add days, excluding weekends?
I’m setting a default follow-up date two days from current date, which currently works: However, I would like to exclude weekends. So I installed moment WeekDay, but I can’t seem to get it to work with adding days to the current date. The documentation calls for: But I can’t get that to work…