普通字符串转价格格式

1.系统方法  console.log((1003457678770.089).toLocaleString());

2.正则方法
String.prototype.toPrice=function(){ return  this.replace(/(?=\B(?:\d{3})+\b)(\d{3}(?:\.\d+$)?)/g,',$1');}
var money = 1003450.89;
alert(money.toString().toPrice());

扩展
Number.prototype.format = function(n, x) {
    var re = '\\d(?=(\\d{' + (x || 3) + '})+' + (n > 0 ? '\\.' : '$') + ')';
    return this.toFixed(Math.max(0, ~~n)).replace(new RegExp(re, 'g'), '$&,');
};
1234..format();           // "1,234"
12345..format(2);         // "12,345.00"
123456.7.format(3, 2);    // "12,34,56.700"
123456.789.format(2, 4);  // "12,3456.79"