js格式化json格式的日期

/*
var val = '/Date(1470067200000)/';
 */
function formatDate(val, formatType) {
    if (val == undefined) {
        return '';
    }
    var reg = /^/Date(d+)/$/;
    if(!reg.test(val)) return'';//格式不正确 ，返回空
    var strDate = val.substr(1, val.length - 2);
    var obj = eval('(' + "{ date :new " + strDate + "}" + ')')
    var date = obj.date;
    var year = date.getFullYear();
    var month = date.getMonth() + 1 < 10 ? '0' + (date.getMonth() + 1) : date.getMonth() + 1;
    var day = date.getDate() < 10 ? '0' + date.getDate() : date.getDate();
    var datetime = year + '-' + month + '-' + day;

    if (formatType == 'yyyy-MM-dd') {
        return datetime;
    } else if (formatType == 'yyyy-MM-dd HH:mm:ss') {
        var hour = date.getHours() < 10 ? '0' + date.getHours() : date.getHours();
        var minute = date.getMinutes() < 10 ? '0' + date.getMinutes() : date.getMinutes();
        var seconds = date.getSeconds() < 10 ? '0' + date.getSeconds() : date.getSeconds();
        return datetime + ' ' + hour + ':' + minute + ':' + seconds;
    }
    return datetime;
}

var val = '/Date(1470067200000)/';

console.log(formatDate(val, 'yyyy-MM-dd'));

结果：