重构的需求
原来的丑×代码如下
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| subjects.each do |m| subject = {} subject[:cno] = m.children[1].text.slice(1..-1).strip subject[:name] = m.children[3].text.slice(1..-1).strip subject[:grade] = m.children[7].text.slice(1..-1).strip subject[:date] = m.children[9].text.slice(1..-1).strip subject[:point] = get_point(subject[:grade]).to_s @guide_score_list << subject end
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我本来想直接改成下面这样
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| @guide_score_list << { cno: m.children[1].text.slice(1..-1).strip, name: m.children[3].text.slice(1..-1).strip, grade: m.children[7].text.slice(1..-1).strip, date: m.children[9].text.slice(1..-1).strip, point: "大写的懵逼" }
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然后发现point
的值要根据grade
来计算,而这样写就只能写成下面这样,更加恶心。
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| get_point(m.children[7].text.slice(1..-1).strip).to_s
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我觉得这段代码重复了好多遍,应该抽出来
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| m.children[i].text.slice(1..-1).strip
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所以就想到了,能不能直接把两个数组元素一对一的,一个为key,一个为value,集合成Hash呢?
甜到掉牙的语法糖
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| keys = [:foo, :bar, :bat] vals = [4, 5, 6]
{foo: 4, bar: 5, bat: 6}
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于是这个风骚的方法就是
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| h = Hash[keys.zip vals]
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这个方案是我从Stack Overflow里查来的,回答的人原话是这样的
h = Hash[a.zip b]
…damn, I love Ruby.
所以代码改成了下面这样,又简洁,又高端,这是最骚的
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| subjects.each do |m| vals = [1, 3, 7, 9].map{ |i| m.children[i].text.slice(1..-1).strip } vals << get_point(vals[2]).to_s keys = [:cno, :name, :grade, :date, :point] @guide_score_list << Hash[keys.zip vals] end
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其他细节
数组等长的情况下,这么做很完美,如果不等长呢?
试一下就知道了
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| keys = [:foo, :bar, :bat] vals = [4, 5, 6, 7] keys.zip vals vals = [4, 5] keys.zip vals
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| kvs = keys.zip vals [keys, vals].transpose == kvs Hash[kvs] == kvs.to_h
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