怎么用js实现把 七分五 转为7.5，五分转为5

怎么用js实现把 七分五 转为7.5，五分转为5
我用了种笨方法，先把数字转为阿拉伯，在把数字提取出来

function _convert(str)
    {
        var arr = ["一","二","三","四","五","六","七","八","九","十"];
        for (var i = 0; i < arr.length; i++) {
            str = str.replace(new RegExp(arr[i], "g"), (i+1));
        }
        return str;
    }

  function getNum(text){
    var value = text.replace(/[^0-9]/ig,"");
    if(value >= 10){
      value=value/1000
    }
    else{
      value=value/100
    }
    return value
    }

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var tranform_hash = {
    '一': '1',
    '二': '2',
    '三': '3',
    '四': '4',
    '五': '5',
    '六': '6',
    '七': '7',
    '八': '8',
    '九': '9',
    '十': '10',
    '分': '.',
};
var str = '';
var chinese = '五分五';
chinese = chinese.replace(/./g, function($1, $2) {
    str += tranform_hash[$1];
})
console.log(str)

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简单的方法可以这样， “七分五”.split("分");

然后分别将七化成7 五化5

然后字符组合

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构造一个键值对应的常数数组，键名为中文，值为对应的阿拉伯数字字符或者小数点