Now I found that the function, given by @Ask does not work as I need. It probably returns the maximum and minimum values of Y in the visible area.

What I need is: I have a curve, currently (i.e.) Xmin= 0,1; Xmax= 0,3; What are the maximum and the minimum values of the curve (data) itself, not the data fitted in the Y extents.

For example, if I have Y:=t*sin(t) the Ymax will be 1 and Ymin will be -1.

That is why I wrote that these values are calculated by the Chart anyway when autozooming.

I will try to write the function myself, if there is problem, I'll ask for help.

Also, I'd like to ask what does the ^ sign stand for? Googling it is hard.

I gave splitting string just as an example, there are plenty solutions, but the function itself is missing as a basic functionality.

I will check your offers, they might be useful for me.