floating point calculations in awk - awk

Question

I am surprised with behaviour of awk while performing floating point calculations. It lead me to wrong calculation on table data.
$ awk 'BEGIN {print 2.3/0.1}'
23 <-- Ok
$ awk 'BEGIN {print int(2.3/0.1)}'
22 <-- Wrong!
$ awk 'BEGIN {print 2.3-2.2==0.1}'
0 <-- Surprise!
$ awk 'BEGIN {print 2.3-2.2>0.1}' <-- Din't produce any output :(
$ awk 'BEGIN {print 2.3-2.2<0.1}'
1 <-- Totally confused now ...
Can somebody throw light as to what's happing here?
EDIT 1
As pointed by #fedorqui, output of second last command goes to file named 0.1 because of redirection operator (>).
Then how am I supposed to perform greater than (>) operation?
Solution to it is also given by #fedorqui
$ awk 'BEGIN {print (2.3-2.2>0.1)}'
0 <-- Wrong!

Answer 1

The following section from the manual should help you understand the issue you're observing:
15.1.1.2 Floating Point Numbers Are Not Abstract Numbers
Unlike numbers in the abstract sense (such as what you studied in high
school or college arithmetic), numbers stored in computers are limited
in certain ways. They cannot represent an infinite number of digits,
nor can they always represent things exactly. In particular,
floating-point numbers cannot always represent values exactly. Here is
an example:
$ awk '{ printf("%010d\n", $1 * 100) }'
515.79
-| 0000051579
515.80
-| 0000051579
515.81
-| 0000051580
515.82
-| 0000051582
Ctrl-d
This shows that some values can be represented exactly, whereas others
are only approximated. This is not a “bug” in awk, but simply an
artifact of how computers represent numbers.
A highly recommended reading:
What every computer scientist should know about floating-point arithmetic