set textarea default line number

To set a default line number for a textarea, you would have to use the "rows" attribute in HTML. The "rows" attribute specifies the visible number of lines in a text area.

For example, if you want to set the default line number to 5, you would do it like this:

<textarea rows="5"></textarea>

Please note that this only sets the visible number of lines in the text area. The user can still input more lines than this, but would need to scroll to see them.