Ruby Cookbook

终于狠了心买了《Ruby Cookbook》，电子版本看着太费眼神，纸质的感觉始终留着书香：）决定好好看看Ruby，因为写RoR的时候，感觉Ruby基础太弱，以致于很多概念，包括Plugin的使用都不是很顺手，以后每天都抽出时间看几个Recipe，嘿嘿，Ok，let's
look at it.

Recipse 1.1 Building a String from Parts

hash = {'key1'=>'val1','key2'=>'val2'}
string = ""

# don't code like following,
# because it makes new String object,wastes time and memory
hash.each {|k,v| string << "#{k} is #{v}\n"}

# more efficient way like this:
hash.each {|k,v| string << k << " is " << v << "\n" }

data = ['1','2','3']
data.join('|')
# => 123
# another way to simulate the behavio of Array#join across an iteration
s=""
data.each_with_index {|x,i| s << x; s << "|" if i < data.length-1 }
puts s
# => 123