UNIX for Dummies Questions & Answers

Hi everybody,
I have been going through a shell scripting book and I have been given a suggestion that says

${bindir} has an advantage over $bindir in the following scenario:

bindir="/usr/local/bin"

exceptions="${bindir}/exc" is better than
exceptions="$bindir/exc" and that the latter might give errors.

But when I echoed them, I got the same result in both cases.

Can you explain me what the text book was trying to convey, and why I didn't get any errors?

For this case it may not matter, but if you have something like

num="Number"

then

${num}3 and $num3 will give different results.

I would always go with "${bindir}/exc" rather than "$bindir/exc" because the former is more readable. I use understandable variable names, blank lines, superfluous parentheses, etc for the same reason.

And yes, the more readable the code, the fewer the errors.... made by the programmmer. Write a complex program with dozens of variables but only use the letters x and y in your variable names. This won't matter to the computer, but it matters a lot to the programmer. You will have many more errors than if you had used readable variable names.