From: Wayne Brissette <waynefb@...>
Date: 2011-10-11T19:32:32+09:00
Subject: Re: why does `a + f b` not parse?

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On Oct 11, 2011, at 2:54 AM, Martin DeMello wrote:

> ruby-1.9.2-p0 > 2 + sqrt 5
> SyntaxError: (irb):25: syntax error, unexpected tINTEGER, expecting
> keyword_do or '{' or '('
> 	from /home/martin/.rvm/rubies/ruby-1.9.2-p0/bin/irb:17:in =
`<main>'
>=20
> I can't see why that doesn't parse properly.
>=20
> martin
>=20

You have two options. First, you can tell ruby what library it needs to =
load (in this case the Math library), or you can include it. You also =
have to surround your number in parentheses ().=20

This means your code would either look like this:

ruby-1.9.2-p290 :004 > 2 + Math.sqrt(5)
 =3D> 4.23606797749979=20

OR=20

ruby-1.9.2-p290 :005 > include Math
 =3D> Object=20
ruby-1.9.2-p290 :006 > 2 + sqrt(5)
 =3D> 4.23606797749979=20


Ironically, as somebody new to Ruby, I was just reading about Libraries =
and Modules so your question was a good review for me. ;)

Wayne



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