js实现金额的大写转小写

function aNumber(num) {

    var numArray = new Array();

    var unit = "亿万元$";

    for (var i = 0; i < unit.length; i++) {

        var re = eval("/" + (numArray[i - 1] ? unit.charAt(i - 1) : "") + "(.*)" + unit.charAt(i) + "/");

        if (num.match(re)) {

            numArray[i] = num.match(re)[1].replace(/^拾/, "壹拾");

            numArray[i] = numArray[i].replace(/[零壹贰叁肆伍陆柒捌玖]/g, function ($1) {

                return "零壹贰叁肆伍陆柒捌玖".indexOf($1);

            });

            numArray[i] = numArray[i].replace(/[分角拾佰仟]/g, function ($1) {

                return "*" + Math.pow(10, "分角 拾佰仟 ".indexOf($1) - 2) + "+"

            }).replace(/^\\*|\\+$/g, "").replace(/整/, "0");

            numArray[i] = "(" + numArray[i] + ")*" + Math.ceil(Math.pow(10, (2 - i) * 4));

        } else

            numArray[i] = 0;

    }

    return eval(numArray.join("+"));

}