How to remove blank lines from a text file?

Question

JavaScript

Given

Text file with many lines
There are lines with text and empty lines
Empty lines contain tabs (tab) (\t)
Lines with text also contain tabs

Question

How to delete lines with tabs (or without them) in which there is no text

Answer 1

it is not clear where this code comes from, but the submit_url variable is written in the code, but it is not clear where it is applied

Answer 2

\n\t+\n
Here is a regular expression that will find empty strings.
What to do next with them is up to you, your task is not clear from the tags.

Answer 3

sed '/^\s*$/d' -i filename

Answer 4

If the question is about programming, then it should be solved accordingly.
And for everyday use:
findstr /v "^\s?[\r\n]+$" file.txt