数组转换到Hash麻烦一点，自己写一个方法to_hash：

复制代码 代码如下:
irb(main):023:0> class Array
irb(main):024:1>   def to_hash
irb(main):025:2>     unless size%2 == 0
irb(main):026:3>       raise "array with odd number of elements"
irb(main):027:3>     end
irb(main):028:2>     hash = Hash.new
irb(main):029:2>     0.step(size-1,2) {|x| hash[self[x]] = self[x+1] }
irb(main):030:2>     hash
irb(main):031:2>   end
irb(main):032:1> end
=> nil

irb(main):033:0> x=[1,2,3,4,5,6]
=> [1, 2, 3, 4, 5, 6]

irb(main):034:0> x.to_hash
=> {5=>6, 1=>2, 3=>4}

11. Hash的丢值行为"codetitle">复制代码 代码如下:
irb(main):001:0> h=Hash.new
=> {}
irb(main):002:0> x=[1,2,3]
=> [1, 2, 3]
irb(main):003:0> h[x]=4
=> 4
irb(main):004:0> h[x]
=> 4
irb(main):005:0> x<<4
=> [1, 2, 3, 4]
irb(main):006:0> h[x]