Identifying and manipulating non-breaking spaces

Non-breaking spaces are one of those weird little things in the computer that you have to keep your eye on. They can cause a lot of problems if they are assumed to be normal spaces. I found a non-breaking space “out in the wild” and decided to use it as an opportunity to explore what it was and better prepare myself for when I encounter more of these beasts.

I’ve been working with some markdown files which were converted from html files and at the bottom of one of these files, I noticed something strange. It looked not at all unusual in notepad (see below)

Figure 1. Screenshot of a file inside Notepad

but when I cut and pasted the file into RStudio, it changed.

Figure 2. Screenshot of a file inside RStudio

There were now a couple of pink dots at the bottom of the file. Ignore the three consecutive colons for now, as they are not important.

So what are these pink dots, exactly? I used cut and paste to insert this strange character into a character string in R

tst1 <- "?"
tst1

## [1] "?"

That’s strange. When you move the pink dot, it disappears and it doesn’t look like you can get it again by printing it. But it is not a blank. The charToRaw function will convert any character string to the equivalent hexadecimal code.

charToRaw(tst1)

## [1] 3f

The hexadecimal code, a0, is not the normal blank character, which is hexadecimal 20. It appears in some html files, especially to keep multiple blank lines from collapsing to a single blank line. The code in html is   and this file, which was converted from a file originally in html format converted the non-breaking space into hexadecimal a0.

If you want to search for non-breaking spaces in a text file, use the code \xa0 in R.

tst1=="\xa0"

## [1] FALSE

Wikipedia has a nice page about non-breaking spaces.