From: dblack@... Date: 2002-09-27T10:05:40+09:00 Subject: Re: Ruby - common pitfalls? Hi -- [ I tried to write by private email as you'd asked, but: ... while talking to mx.glue.umd.edu.: >>> MAIL From: <<< 550 5.0.0 Sorry,no access for this domain 554 5.0.0 Service unavailable ] On Fri, 27 Sep 2002, William Djaja Tjokroaminata wrote: > 6) Array.new (2, Hash.new) returns an array with two elements referencing > the same, indentical hash, and not two independent hashes. Also if you don't close the space before the (, you'll get a warning (at least with -w). The whole whitespace-before-parens thing might be worth an entry of its own. > 7) After reading data from a file and putting them into variables, the > data type is really String. To convert them into numbers, use the > "to_i" or "to_f" methods. If you use the "+" operator to add the > "numbers" without calling the conversion methods, for example, you will > simply concatenate the strings. You can use the new scanf to get around this. I don't know whether references to library stuff is outside the scope of what you want to cover/include here -- but anyway, just in case, its home is: . David -- David Alan Black | Register for RubyConf 2002! home: dblack@candle.superlink.net | November 1-3 work: blackdav@shu.edu | Seattle, WA, USA Web: http://pirate.shu.edu/~blackdav | http://www.rubyconf.com David -- David Alan Black | Register for RubyConf 2002! home: dblack@candle.superlink.net | November 1-3 work: blackdav@shu.edu | Seattle, WA, USA Web: http://pirate.shu.edu/~blackdav | http://www.rubyconf.com