How to make a new line in the source file but not the output

Question

I want to adhere to the traditional '80 character' line length limit in my .tex source file.

How do I do a new line in the source but not in the document output?

Answer 1

From the TeXbook, p. 25

And now comes the good news, if you haven't used computer typesetting before: You don't have to worry about where to break lines in a paragraph (i.e., where to stop at the right margin and to begin a new line), because TeX will do that for you. Your manuscript file can contain long lines or short lines, or both; it doesn't matter. This is especially helpful when you make changes, since you don't have to retype anything except the words that changed. Every time you begin a new line in your manuscript file it is essentially the same as typing a space. When TeX has read an entire paragraph—in this case lines 7 to 11—it will try to break up the text so that each line of output, except the last, contains about the same amount of copy; and it will hyphenate words if necessary to keep the spacing consistent, but only as a last resort.

Remember also that spaces are ignored at the start of a line and that a sequence of spaces is equivalent to one. However, a blank line will count as an end of paragraph command.

Answer 2

It helps to use linebreaks wisely: Indent your LaTeX source for readability, split lines at punctuation or into phrases. That way most changes involve shuffling lines around, which is easier than snipping and pasting between lines.