Remove Blank Lines Tool

How it is calculated

The text is split at every line break (Windows \r\n, old Mac \r or Unix \n). A line is dropped when it has nothing left after ordinary spaces, tabs and line-break characters are trimmed away; every other line is kept exactly as typed and the survivors are joined with plain \n line breaks. Because only the test uses trimming, indentation and trailing spaces on kept lines stay untouched. The counts are removed = total lines − kept lines. A newline at the very end of the input creates one more empty line, so it is counted as a removed line. Input that is empty or only whitespace gives no result. Lines are never merged, reordered or de-duplicated.

Common mistakes

• Expecting this to collapse several blank lines into one; every blank line is removed, so paragraphs lose their separating gap.
• Thinking that a line with only a space or tab survives because it looks empty; whitespace-only lines are removed too.
• Being surprised that the removed count is one higher than the visible blank lines, when the pasted text ends with a line break.
• Expecting leading or trailing spaces on the remaining lines to be trimmed; only the blank-line test trims, the lines themselves are copied unchanged.
• Expecting lines that hold only a non-breaking space or a zero-width space to disappear; they look empty but are kept, because only ordinary spaces, tabs and line-break characters count as blank.