[JavaScript] 时间戳格式化为yyyy-MM-dd日期

function formateDate(timestamp){
    var date =  new Date(timestamp);
    var y = 1900+date.getYear();
    var m = "0"+(date.getMonth()+1);
    var d = "0"+date.getDate();
    return y+"-"+m.substring(m.length-2,m.length)+"-"+d.substring(d.length-2,d.length);
}