js日期格式化，工具类中

/**
 * for vue: 日期格式化
 **/function dateFormat(value, format) {
    if (typeof(value) == "undefined" || value == null || value == '') {
        return value;
    }
    var date = new Date(value);
    format = format || 'yyyy-MM-dd';
    var o = {
        "M+": date.getMonth() + 1, //month
        "d+": date.getDate(), //day
        "h+": date.getHours(), //hour
        "m+": date.getMinutes(), //minute
        "s+": date.getSeconds(), //second
        "q+": Math.floor((date.getMonth() + 3) / 3), //quarter
        "S": date.getMilliseconds() //millisecond
    }
    if (/(y+)/.test(format)) format = format.replace(RegExp.$1,
        (date.getFullYear() + "").substr(4 - RegExp.$1.length));
    for (var k in o)
        if (new RegExp("(" + k + ")").test(format))
            format = format.replace(RegExp.$1,
                RegExp.$1.length == 1 ? o[k] :
                ("00" + o[k]).substr(("" + o[k]).length));
    return format;
};