I just wasted 2 hours trying to figure out why the properties of a destructured object returned undefined, even though everything was fine in JSON format. Tried to request data on the frontend from my server with a database attached. Tried accessing each object of my array separately, it worked. In a loop: dataArray[index].propertyX ... undefined??
Turns out I used the wrong property names to access the info inside each object.
🤦

At the very start when I learned my first language. Didn't know where to find the "{" and "}" keys on the keyboard. Thought I would never be a dev, since I couldn't write a program without those keys.
Or when I didn't understand the notation of accessing values inside an array. Thought things like array[0] would do some magic to the array and didn't know how to access other parts of an array. I was following a book back then.

And now I've run into a whole another issue which is really fucking strange.

Has it ever occured that a Object in java looses all it's values after being put into an array of same type?

My problem:

[code...]

Mat[] matArray = new Mat[totalFramesOfVideo];

videoCapture.open();

Mat currentFrame = new Mat();
int frameCounter = 0;
while(videoCapture.read()) {

currentFrame = (last read frame as a Mat)

matArray[frameCounter] = currentFrame;

frameCounter++;
}

then, after filling the array and accessing elements, they lose all their object values.
Eg. Before currentFrame's dimensions were 1080*1920, but matArray[index] dimensions are suddenly 0*0.