javascript 时间戳转换为日期格式

function timestampToTime(timestamp) {
if(timestamp != null && timestamp != undefined && timestamp != ""){
if(timestamp.length == 10){
timestame = timestamp 1000;//时间戳为10位需1000，时间戳为13位的话不需乘1000
}
var date = new Date(timestamp);
var Y = date.getFullYear() + '-';
var M = (date.getMonth()+1 < 10 ? '0'+(date.getMonth()+1) : date.getMonth()+1) + '-';
var D = (date.getDate() < 10 ? '0'+date.getDate() : date.getDate()) + ' ';
var h = (date.getHours() < 10 ? '0'+date.getHours() : date.getHours()) + ':';
var m = (date.getMinutes() < 10 ? '0'+date.getMinutes() : date.getMinutes()) + ':';
var s = (date.getSeconds() < 10 ? '0'+date.getSeconds() : date.getSeconds());
return Y+M+D+h+m+s;
}
return "";
}