I have two dates in javascript:
var first = '2012-11-21';
var second = '2012-11-03';
i would like make:
if(first > second){
//...
}
how is the best way for this, without external library?
I have two dates in javascript:
var first = '2012-11-21';
var second = '2012-11-03';
i would like make:
if(first > second){
//...
}
how is the best way for this, without external library?
if( (new Date(first).getTime() > new Date(second).getTime()))
{
----------------------------------
}
If your dates are strings in a strict yyyy-mm-dd
format as shown in the question then your code will work as is without converting to date objects or numbers:
if(first > second){
...will do a lexographic (i.e., alphanumeric "dictionary order") string comparison - which will compare the first characters of each string, then the second characters of each string, etc. Which will give the result you want...
You can do this way, it will work fine:
var date1 = new Date('2013-07-30');
var date2 = new Date('2013-07-30');
if(date1 === date2){ console.log("both are equal");} //it does not work
==>undefined //result
if(+date1 === +date2){ console.log("both are equal");} //do it this way!
//(use + prefix for a variable that holds a date value)
==> both are equal //result
Note :- don't forget to use a + prefix
The best way is,
var first = '2012-11-21';
var second = '2012-11-03';
if (new Date(first) > new Date(second) {
.....
}
Because of your date format, you can use this code:
if(parseInt(first.replace(/-/g,""),10) > parseInt(second.replace(/-/g,""),10)){
//...
}
It will check whether 20121121
number is bigger than 20121103
or not.
USe this function for date comparison in javascript:
function fn_DateCompare(DateA, DateB) {
var a = new Date(DateA);
var b = new Date(DateB);
var msDateA = Date.UTC(a.getFullYear(), a.getMonth()+1, a.getDate());
var msDateB = Date.UTC(b.getFullYear(), b.getMonth()+1, b.getDate());
if (parseFloat(msDateA) < parseFloat(msDateB))
return -1; // less than
else if (parseFloat(msDateA) == parseFloat(msDateB))
return 0; // equal
else if (parseFloat(msDateA) > parseFloat(msDateB))
return 1; // greater than
else
return null; // error
}
you can done this way also.
if (dateFormat(first, "yyyy-mm-dd") > dateFormat(second, "yyyy-mm-dd")) {
console.log("done");
}
OR
if (dateFormat(first, "mm-dd-yyyy") > dateFormat(second, "mm-dd-yyyy")) {
console.log("done");
}
i use following plugin for dateFormat()
var dateFormat = function () {
var token = /d{1,4}|m{1,4}|yy(?:yy)?|([HhMsTt])\1?|[LloSZ]|"[^"]*"|'[^']*'/g,
timezone = /\b(?:[PMCEA][SDP]T|(?:Pacific|Mountain|Central|Eastern|Atlantic) (?:Standard|Daylight|Prevailing) Time|(?:GMT|UTC)(?:[-+]\d{4})?)\b/g,
timezoneClip = /[^-+\dA-Z]/g,
pad = function (val, len) {
val = String(val);
len = len || 2;
while (val.length < len) val = "0" + val;
return val;
};
// Regexes and supporting functions are cached through closure
return function (date, mask, utc) {
var dF = dateFormat;
// You can't provide utc if you skip other args (use the "UTC:" mask prefix)
if (arguments.length == 1 && Object.prototype.toString.call(date) == "[object String]" && !/\d/.test(date)) {
mask = date;
date = undefined;
}
// Passing date through Date applies Date.parse, if necessary
date = date ? new Date(date) : new Date;
if (isNaN(date)) throw SyntaxError("invalid date");
mask = String(dF.masks[mask] || mask || dF.masks["default"]);
// Allow setting the utc argument via the mask
if (mask.slice(0, 4) == "UTC:") {
mask = mask.slice(4);
utc = true;
}
var _ = utc ? "getUTC" : "get",
d = date[_ + "Date"](),
D = date[_ + "Day"](),
m = date[_ + "Month"](),
y = date[_ + "FullYear"](),
H = date[_ + "Hours"](),
M = date[_ + "Minutes"](),
s = date[_ + "Seconds"](),
L = date[_ + "Milliseconds"](),
o = utc ? 0 : date.getTimezoneOffset(),
flags = {
d: d,
dd: pad(d),
ddd: dF.i18n.dayNames[D],
dddd: dF.i18n.dayNames[D + 7],
m: m + 1,
mm: pad(m + 1),
mmm: dF.i18n.monthNames[m],
mmmm: dF.i18n.monthNames[m + 12],
yy: String(y).slice(2),
yyyy: y,
h: H % 12 || 12,
hh: pad(H % 12 || 12),
H: H,
HH: pad(H),
M: M,
MM: pad(M),
s: s,
ss: pad(s),
l: pad(L, 3),
L: pad(L > 99 ? Math.round(L / 10) : L),
t: H < 12 ? "a" : "p",
tt: H < 12 ? "am" : "pm",
T: H < 12 ? "A" : "P",
TT: H < 12 ? "AM" : "PM",
Z: utc ? "UTC" : (String(date).match(timezone) || [""]).pop().replace(timezoneClip, ""),
o: (o > 0 ? "-" : "+") + pad(Math.floor(Math.abs(o) / 60) * 100 + Math.abs(o) % 60, 4),
S: ["th", "st", "nd", "rd"][d % 10 > 3 ? 0 : (d % 100 - d % 10 != 10) * d % 10]
};
return mask.replace(token, function ($0) {
return $0 in flags ? flags[$0] : $0.slice(1, $0.length - 1);
});
};
}();
// Some common format strings
dateFormat.masks = {
"default": "ddd mmm dd yyyy HH:MM:ss",
shortDate: "m/d/yy",
mediumDate: "mmm d, yyyy",
longDate: "mmmm d, yyyy",
fullDate: "dddd, mmmm d, yyyy",
shortTime: "h:MM TT",
mediumTime: "h:MM:ss TT",
longTime: "h:MM:ss TT Z",
isoDate: "yyyy-mm-dd",
isoTime: "HH:MM:ss",
isoDateTime: "yyyy-mm-dd'T'HH:MM:ss",
isoUtcDateTime: "UTC:yyyy-mm-dd'T'HH:MM:ss'Z'"
};
// Internationalization strings
dateFormat.i18n = {
dayNames: [
"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"
],
monthNames: [
"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"
]
};
// For convenience...
Date.prototype.format = function (mask, utc) {
return dateFormat(this, mask, utc);
};