I want to change the artboard and the data/content size which is present in each artboard at the same time instead of having too manually. When I am trying to change the size of artboard it is just changing the size of artboard instead of all the content. Below is the video link for clarification of what happening.
Why do you need to do this? If it’s vector it will scale to any size?
Scale it on output.
Yes I know the issues is I have total 8 artboards in the scene. I have to do it manually each, which is time-consuming. If it is possible to just change the artboard size than the content which is present in each artboard change automatically with respect to their artboard then it will be a time saver.
Can you elaborate on the end product here?
You should just scale it on output - it’s easiest to do.
The best I can find is a script
Thanks for sharing the script method. Unfortunately I have no prior experience regarding the script as I have never used it before. So is there is any other way to this without script?
I shared a video link there with the how to use scripts.
It’s quite easy.
It’s the only way I know.
Can you share your workflow and what you’re trying to achieve?
I still think you can just resize it to whatever size you need on output - there’s really no need to change the artboard and scale the objects.
Can you share your workflow and what you’re trying to achieve?
I am currently creating the mobile application UI Design in Adobe Illustrator. Now the issue is I have created I have created all the different screens of mobile application UI. Now I am changing the size of the art board to mobile screen actual size due to which I want to change the screen artboard size along with content. I know I should set the screen size before started working on the actual UI which I did not do it unfortunately. Anyway thanks for the assistance mate. 
Select your items you want to output
File>Export Selection
Choose your format - and your Width from the drop downs
But there is no actual size given by which we can set the height and weight. The above method just scale the object.
Yes, you want to keep the ratio, right? So you can export to any width or height you want.
Are you looking to change the ratio?
I don’t get it how can I export to any height or weight if the option of export any hieght and width is not present in export selection?
See. Just the scale option is present in here.
Click the arrow beside the 1x and select width or height.
So for the late response. This option is only giving me one response whether I can change the height or width but not both. See
It’s in proportion. Just have to pick either what width or what height you want it.
But I want both. That’s the thing I want to change my size of art board along with their respected data/content to 1800 px width and 900 px height.
Yes - and if your artboard is 900 px wide and 450 px height.
The put the width as 1800px and it will automatically adjust the height to 900px.
Have you even tried it?
Yes I have tried it is not making the actual size which I am setting. I have set to make 1800 PX width and 900 PX height, but when I open that converted file in Adobe Illustrator to check the artboard size it is showing different. Below is the video link for clarification:
Why open the exported file back into Illustrator? Just open it in Photoshop, or just check the file info and see that the pixel information is correct.
I’d ask the same thing, and that’s just one of many questions I’d ask. Honestly, your workflow seems awfully convoluted, with mixed units of measure, rasterized body type, and conclusions based on a sequence of events that makes little sense.
Raster export from Illustrator is a minefield. If you need raster images of particular dimensions, set up a Photoshop canvas of that size (and suitable resolution), put your Illustrator content on it as a Smart Object, adjust the fit, and save.
Sticking with Asset Export from Illustrator should be fine. But there is no physical measurement for a pixel. So, using some website to try and figure out how millimeters convert to pixels is worthless.
If you really want to test in Illustrator, create a new web based artboard measured in pixels. But, that is still overkill … just right click on the file on your computer and “get info” (at least on a Mac) and it will show you the pixel size of any graphic. I know a PC displays the pixel info as well, I believe it is also accessible by right clicking, I’m sure a PC user can clarify.