如何在JavaScript中将一种日期格式转换为另一种格式？
示例：
旧格式是
YYYY / MM / DD
但我想将其转换为
DD-MM-YYYY
答案 0 :(得分：5)
我认为您可以使用jQuery UI库的datepicker：使用parseDate方法将字符串转换为Date对象，然后使用formatDate将Date对象转换为另一个字串。检查网站上提供的样本;它们包括格式修饰符。
答案 1 :(得分：2)
这里 -
// Utility function to append a 0 to single-digit numbers
Date.LZ = function(x) {return(x<0||x>9?"":"0")+x};
// Full month names. Change this for local month names
Date.monthNames = new Array('January','February','March','April','May','June','July','August','September','October','November','December');
// Month abbreviations. Change this for local month names
Date.monthAbbreviations = new Array('Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec');
// Full day names. Change this for local month names
Date.dayNames = new Array('Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday');
// Day abbreviations. Change this for local month names
Date.dayAbbreviations = new Array('Sun','Mon','Tue','Wed','Thu','Fri','Sat');
// Used for parsing ambiguous dates like 1/2/2000 - default to preferring 'American' format meaning Jan 2.
// Set to false to prefer 'European' format meaning Feb 1
Date.preferAmericanFormat = true;
// If the getFullYear() method is not defined, create it
if (!Date.prototype.getFullYear) {
Date.prototype.getFullYear = function() { var yy=this.getYear(); return (yy<1900?yy+1900:yy); } ;
}
// Parse a string and convert it to a Date object.
// If no format is passed, try a list of common formats.
// If string cannot be parsed, return null.
// Avoids regular expressions to be more portable.
Date.parseString = function(val, format) {
// If no format is specified, try a few common formats
if (typeof(format)=="undefined" || format==null || format=="") {
var generalFormats=new Array('y-M-d','MMM d, y','MMM d,y','y-MMM-d','d-MMM-y','MMM d','MMM-d','d-MMM');
var monthFirst=new Array('M/d/y','M-d-y','M.d.y','M/d','M-d');
var dateFirst =new Array('d/M/y','d-M-y','d.M.y','d/M','d-M');
var checkList=new Array(generalFormats,Date.preferAmericanFormat?monthFirst:dateFirst,Date.preferAmericanFormat?dateFirst:monthFirst);
for (var i=0; i<checkList.length; i++) {
var l=checkList[i];
for (var j=0; j<l.length; j++) {
var d=Date.parseString(val,l[j]);
if (d!=null) {
return d;
}
}
}
return null;
};
this.isInteger = function(val) {
for (var i=0; i < val.length; i++) {
if ("1234567890".indexOf(val.charAt(i))==-1) {
return false;
}
}
return true;
};
this.getInt = function(str,i,minlength,maxlength) {
for (var x=maxlength; x>=minlength; x--) {
var token=str.substring(i,i+x);
if (token.length < minlength) {
return null;
}
if (this.isInteger(token)) {
return token;
}
}
return null;
};
val=val+"";
format=format+"";
var i_val=0;
var i_format=0;
var c="";
var token="";
var token2="";
var x,y;
var year=new Date().getFullYear();
var month=1;
var date=1;
var hh=0;
var mm=0;
var ss=0;
var ampm="";
while (i_format < format.length) {
// Get next token from format string
c=format.charAt(i_format);
token="";
while ((format.charAt(i_format)==c) && (i_format < format.length)) {
token += format.charAt(i_format++);
}
// Extract contents of value based on format token
if (token=="yyyy" || token=="yy" || token=="y") {
if (token=="yyyy") {
x=4;y=4;
}
if (token=="yy") {
x=2;y=2;
}
if (token=="y") {
x=2;y=4;
}
year=this.getInt(val,i_val,x,y);
if (year==null) {
return null;
}
i_val += year.length;
if (year.length==2) {
if (year > 70) {
year=1900+(year-0);
}
else {
year=2000+(year-0);
}
}
}
else if (token=="MMM" || token=="NNN"){
month=0;
var names = (token=="MMM"?(Date.monthNames.concat(Date.monthAbbreviations)):Date.monthAbbreviations);
for (var i=0; i<names.length; i++) {
var month_name=names[i];
if (val.substring(i_val,i_val+month_name.length).toLowerCase()==month_name.toLowerCase()) {
month=(i%12)+1;
i_val += month_name.length;
break;
}
}
if ((month < 1)||(month>12)){
return null;
}
}
else if (token=="EE"||token=="E"){
var names = (token=="EE"?Date.dayNames:Date.dayAbbreviations);
for (var i=0; i<names.length; i++) {
var day_name=names[i];
if (val.substring(i_val,i_val+day_name.length).toLowerCase()==day_name.toLowerCase()) {
i_val += day_name.length;
break;
}
}
}
else if (token=="MM"||token=="M") {
month=this.getInt(val,i_val,token.length,2);
if(month==null||(month<1)||(month>12)){
return null;
}
i_val+=month.length;
}
else if (token=="dd"||token=="d") {
date=this.getInt(val,i_val,token.length,2);
if(date==null||(date<1)||(date>31)){
return null;
}
i_val+=date.length;
}
else if (token=="hh"||token=="h") {
hh=this.getInt(val,i_val,token.length,2);
if(hh==null||(hh<1)||(hh>12)){
return null;
}
i_val+=hh.length;
}
else if (token=="HH"||token=="H") {
hh=this.getInt(val,i_val,token.length,2);
if(hh==null||(hh<0)||(hh>23)){
return null;
}
i_val+=hh.length;
}
else if (token=="KK"||token=="K") {
hh=this.getInt(val,i_val,token.length,2);
if(hh==null||(hh<0)||(hh>11)){
return null;
}
i_val+=hh.length;
hh++;
}
else if (token=="kk"||token=="k") {
hh=this.getInt(val,i_val,token.length,2);
if(hh==null||(hh<1)||(hh>24)){
return null;
}
i_val+=hh.length;
hh--;
}
else if (token=="mm"||token=="m") {
mm=this.getInt(val,i_val,token.length,2);
if(mm==null||(mm<0)||(mm>59)){
return null;
}
i_val+=mm.length;
}
else if (token=="ss"||token=="s") {
ss=this.getInt(val,i_val,token.length,2);
if(ss==null||(ss<0)||(ss>59)){
return null;
}
i_val+=ss.length;
}
else if (token=="a") {
if (val.substring(i_val,i_val+2).toLowerCase()=="am") {
ampm="AM";
}
else if (val.substring(i_val,i_val+2).toLowerCase()=="pm") {
ampm="PM";
}
else {
return null;
}
i_val+=2;
}
else {
if (val.substring(i_val,i_val+token.length)!=token) {
return null;
}
else {
i_val+=token.length;
}
}
}
// If there are any trailing characters left in the value, it doesn't match
if (i_val != val.length) {
return null;
}
// Is date valid for month?
if (month==2) {
// Check for leap year
if ( ( (year%4==0)&&(year%100 != 0) ) || (year%400==0) ) { // leap year
if (date > 29){
return null;
}
}
else {
if (date > 28) {
return null;
}
}
}
if ((month==4)||(month==6)||(month==9)||(month==11)) {
if (date > 30) {
return null;
}
}
// Correct hours value
if (hh<12 && ampm=="PM") {
hh=hh-0+12;
}
else if (hh>11 && ampm=="AM") {
hh-=12;
}
return new Date(year,month-1,date,hh,mm,ss);
};
// Check if a date string is valid
Date.isValid = function(val,format) {
return (Date.parseString(val,format) != null);
};
// Check if a date object is before another date object
Date.prototype.isBefore = function(date2) {
if (date2==null) {
return false;
}
return (this.getTime()<date2.getTime());
};
// Check if a date object is after another date object
Date.prototype.isAfter = function(date2) {
if (date2==null) {
return false;
}
return (this.getTime()>date2.getTime());
};
// Check if two date objects have equal dates and times
Date.prototype.equals = function(date2) {
if (date2==null) {
return false;
}
return (this.getTime()==date2.getTime());
};
// Check if two date objects have equal dates, disregarding times
Date.prototype.equalsIgnoreTime = function(date2) {
if (date2==null) {
return false;
}
var d1 = new Date(this.getTime()).clearTime();
var d2 = new Date(date2.getTime()).clearTime();
return (d1.getTime()==d2.getTime());
};
// Format a date into a string using a given format string
Date.prototype.format = function(format) {
format=format+"";
var result="";
var i_format=0;
var c="";
var token="";
var y=this.getYear()+"";
var M=this.getMonth()+1;
var d=this.getDate();
var E=this.getDay();
var H=this.getHours();
var m=this.getMinutes();
var s=this.getSeconds();
var yyyy,yy,MMM,MM,dd,hh,h,mm,ss,ampm,HH,H,KK,K,kk,k;
// Convert real date parts into formatted versions
var value=new Object();
if (y.length < 4) {
y=""+(+y+1900);
}
value["y"]=""+y;
value["yyyy"]=y;
value["yy"]=y.substring(2,4);
value["M"]=M;
value["MM"]=Date.LZ(M);
value["MMM"]=Date.monthNames[M-1];
value["NNN"]=Date.monthAbbreviations[M-1];
value["d"]=d;
value["dd"]=Date.LZ(d);
value["E"]=Date.dayAbbreviations[E];
value["EE"]=Date.dayNames[E];
value["H"]=H;
value["HH"]=Date.LZ(H);
if (H==0){
value["h"]=12;
}
else if (H>12){
value["h"]=H-12;
}
else {
value["h"]=H;
}
value["hh"]=Date.LZ(value["h"]);
value["K"]=value["h"]-1;
value["k"]=value["H"]+1;
value["KK"]=Date.LZ(value["K"]);
value["kk"]=Date.LZ(value["k"]);
if (H > 11) {
value["a"]="PM";
}
else {
value["a"]="AM";
}
value["m"]=m;
value["mm"]=Date.LZ(m);
value["s"]=s;
value["ss"]=Date.LZ(s);
while (i_format < format.length) {
c=format.charAt(i_format);
token="";
while ((format.charAt(i_format)==c) && (i_format < format.length)) {
token += format.charAt(i_format++);
}
if (typeof(value[token])!="undefined") {
result=result + value[token];
}
else {
result=result + token;
}
}
return result;
};
// Get the full name of the day for a date
Date.prototype.getDayName = function() {
return Date.dayNames[this.getDay()];
};
// Get the abbreviation of the day for a date
Date.prototype.getDayAbbreviation = function() {
return Date.dayAbbreviations[this.getDay()];
};
// Get the full name of the month for a date
Date.prototype.getMonthName = function() {
return Date.monthNames[this.getMonth()];
};
// Get the abbreviation of the month for a date
Date.prototype.getMonthAbbreviation = function() {
return Date.monthAbbreviations[this.getMonth()];
};
// Clear all time information in a date object
Date.prototype.clearTime = function() {
this.setHours(0);
this.setMinutes(0);
this.setSeconds(0);
this.setMilliseconds(0);
return this;
};
// Add an amount of time to a date. Negative numbers can be passed to subtract time.
Date.prototype.add = function(interval, number) {
if (typeof(interval)=="undefined" || interval==null || typeof(number)=="undefined" || number==null) {
return this;
}
number = +number;
if (interval=='y') { // year
this.setFullYear(this.getFullYear()+number);
}
else if (interval=='M') { // Month
this.setMonth(this.getMonth()+number);
}
else if (interval=='d') { // Day
this.setDate(this.getDate()+number);
}
else if (interval=='w') { // Weekday
var step = (number>0)?1:-1;
while (number!=0) {
this.add('d',step);
while(this.getDay()==0 || this.getDay()==6) {
this.add('d',step);
}
number -= step;
}
}
else if (interval=='h') { // Hour
this.setHours(this.getHours() + number);
}
else if (interval=='m') { // Minute
this.setMinutes(this.getMinutes() + number);
}
else if (interval=='s') { // Second
this.setSeconds(this.getSeconds() + number);
}
return this;
};
将其复制到.js文件，并将其包含在您的页面中。
然后您可以在Date对象上使用format（）方法。
您还可以找到另一个图书馆here。
答案 2 :(得分：2)
我的日期扩展程序会做得很好 - 它们也可以解析数据格式并进行大量日期数学/比较：
不确定它是否有帮助，但我发现它在几个项目中非常宝贵。日期函数（主要）基于CFML（如果重要的话）。
我并不是说他们比其他选择更好 - 但我为他们感到骄傲，从来没有（好吧......几乎从不）因为选择而受到伤害。
答案 3 :(得分：0)
如果你不使用jQuery（我想不出原因，但以防万一），我已经为Javascript Date对象创建了一个补丁，它允许你从不同格式的字符串中解析日期并转换以不同格式记录字符串。
您可以在我的博客上查看Javascript Date Formatter文章的更多信息。
答案 4 :(得分：0)
我的答案很晚，但我认为以下解决方案对于这个问题来说简单而有效。这总是对我有用。
你走了：
function dateToYMD（date）{ var d = date.getDate（）; var m = date.getMonth（）+ 1; var y = date.getFullYear（）; 返回''+（d <= 9？'0'+ d：d）+' - '+（m <= 9？'0'+ m：m）+' - '+ y; }