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Integer division in programming languages

4^th of August 2004

I have a degree in mathematics and computer science, but still I don't know why different programming languages evaluate Integer/Integer differently. On any calculator if you divide one integer with another you get a decimal number (of course not if the numerator is a factor of the denominator).

Python for example returns a integer number:

 >>> print 3/10
 0
 >>> print 3/10.0
 0.3

Perl on the other hand returns a decimal number:

 print 3/10;  print "\n";
 print 3/10.0;
 ...gives...
 0.3
 0.3

PostgreSQL is like Python:

 database=# SELECT 3/10 AS quotient1, 3/10.0 As quotient2;
 quotient1 |       quotient2
-----------+------------------------
         0 | 0.30000000000000000000

And good old MS Excel gives:

 =3/10  <=> 0.3

Why is it so?

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