Find the most recent date from an Array - arrays

How to find the most recent date from an array like the one below?
Tue Jun 2 17:59:54 GMT+0200 2013
Tue Jun 5 18:00:10 GMT+0200 2013
Tue Jun 1 12:27:14 GMT+0200 2013
Tue Jun 3 17:26:58 GMT+0200 2013
Tue Jun 9 17:27:49 GMT+0200 2013
Tue Jun 1 13:27:39 GMT+0200 2015
Tue Jun 3 12:27:59 GMT+0200 2013
Tue Jun 6 15:27:22 GMT+0200 2014
Tue Jun 2 17:27:30 GMT+0200 2014

Assuming your array is full of AS3 native Date objects, you could simply do this:
array.sortOn("time",Array.DESCENDING);
trace("Most Recent:",array[0]);
You cannot use array.sort (unless you use the Array.NUMERIC flag) because it will sort the string representation of the date. So all your days of the week would then be grouped together instead of the actual date.
If your dates are strings, then you will need to convert them to Date objects prior to sorting:
//assuming your posted array is in a var called 'stringArray'
var dateArray:Array = []; //a new array to hold the converted strings
for(var i:int=0;i<stringArray.length;i++){
dateArray.push(new Date(stringArray[i]));
}
dateArray.sortOn("time",Array.DESCENDING);
trace("Most Recent Date:",dateArray[0]);
To show this in a concrete example, here is your posted dates - copy paste this code to produce the same results:
var arr:Array = new Array(
new Date("Tue Jun 2 17:59:54 GMT+0200 2013"),
new Date("Tue Jun 5 18:00:10 GMT+0200 2013"),
new Date("Tue Jun 1 12:27:14 GMT+0200 2013"),
new Date("Tue Jun 3 17:26:58 GMT+0200 2013"),
new Date("Tue Jun 9 17:27:49 GMT+0200 2013"),
new Date("Tue Jun 1 13:27:39 GMT+0200 2015"),
new Date("Tue Jun 3 12:27:59 GMT+0200 2013"),
new Date("Tue Jun 6 15:27:22 GMT+0200 2014"),
new Date("Tue Jun 2 17:27:30 GMT+0200 2014")
);
arr.sort(Array.DESCENDING);
trace("SORT:");
traceDates();
arr.sortOn("time",Array.DESCENDING);
trace("\nSORT ON:");
traceDates();
function traceDates(){
for(var i:int=0;i<arr.length;i++){
trace(" ",arr[i].fullYear + "-" + arr[i].month + "-" + arr[i].day);
}
}
//OUTPUT:
/*
SORT:
2013-5-3
2013-5-0
2013-5-0
2013-5-6
2013-5-1
2013-5-1
2014-5-1
2015-5-1 //most recent date, second to LAST item in the array
2014-5-5
SORT ON:
2015-5-1 //June 1st is the most recent date (first item in the array)
2014-5-5
2014-5-1
2013-5-0
2013-5-3
2013-5-1
2013-5-1
2013-5-0
2013-5-6
*/

Are they Date objects?
If so, you can compare the time property of each. It will give you the number of milliseconds since Jan 1, 1970. The highest number will be the most recent.
Something along these lines:
var mostRecentDate:Date = dateArray[0];
for(var i:int = 0; i < dateArray.length; i++){
if(dateArray[i].time > mostRecentDate.time){
mostRecentDate = dateArray[i];
}
}

Date objects act like simple Number when it comes to sorting or comparison. All you have to do is treat them like Numbers. So taken from Cadin answer:
dateArray.sort();
var oldestDate:Date = dateArray[0];
Will get you the oldest Date while:
dateArray.sort(Array.DESCENDING);
var mostRecentDate:Date = dateArray[0];
Will get you the most recent one.
For LDMS, this is what I got:
var firstdate:Date = new Date();
var seconddate:Date = new Date();
var thirddate:Date = new Date();
seconddate.time = firstdate.time + 5000000;
thirddate.time = firstdate.time + 50000000;
trace(seconddate > firstdate)//true
trace(firstdate > seconddate)//false
trace(seconddate.time > firstdate.time)//true
var array:Array = [thirddate, firstdate, seconddate];
trace(array)
//Wed Jun 3 03:37:40 GMT-0400 2015,Tue Jun 2 13:44:20 GMT-0400 2015,Tue Jun 2 15:07:40 GMT-0400 2015
array.sort();
trace(array)
//Tue Jun 2 13:44:20 GMT-0400 2015,Tue Jun 2 15:07:40 GMT-0400 2015,Wed Jun 3 03:37:40 GMT-0400 2015
array.sort(Array.DESCENDING);
trace(array)
//Wed Jun 3 03:37:40 GMT-0400 2015,Tue Jun 2 15:07:40 GMT-0400 2015,Tue Jun 2 13:44:20 GMT-0400 2015

Sort the array and grab the first (descending) or last (ascending) element.
Edit: 2 down-votes because I didn't provide an example, or because people don't know you can sort dates? This works:
var dates:Array = [
"Tue Jun 2 17:59:54 GMT+0200 2013",
"Tue Jun 5 18:00:10 GMT+0200 2013",
"Tue Jun 1 12:27:14 GMT+0200 2013",
"Tue Jun 3 17:26:58 GMT+0200 2013",
"Tue Jun 9 17:27:49 GMT+0200 2013",
"Tue Jun 1 13:27:39 GMT+0200 2015",
"Tue Jun 3 12:27:59 GMT+0200 2013",
"Tue Jun 6 15:27:22 GMT+0200 2014",
"Tue Jun 2 17:27:30 GMT+0200 2014"
].map(function(s:String, i:int, a:Array):Date {
return new Date(s);
}).sort(Array.NUMERIC | Array.DESCENDING);
var latest:Date = dates[0]; // Mon Jun 1 07:27:39 GMT-0400 2015
The problem is the OP did not make it clear what kind of data they are working with (strings or Date objects) so the exact solution code is unknown.

Related

how to take only times from dates inside array in rails

so... i need to take times from dates inside Array
so for example I have an array like this
a = [
Thu, 17 Mar 2022 10:00:00.000000000 KST +09:00,
Thu, 17 Mar 2022 10:00:00.000000000 KST +09:00,
Thu, 17 Mar 2022 14:00:00.000000000 KST +09:00,
Thu, 17 Mar 2022 14:00:00.000000000 KST +09:00,
Thu, 17 Mar 2022 17:00:00.000000000 KST +09:00]
and wanted to have result of
a = ["10:00", "10:00", "14:00", "14:00", "17:00"]
So i was trying this
can_choose =[];
a.each_with_index do |time| strftime("%H:%M")
can_choose <<|time|
but doesn't works at all...
where should I have to fix??
You can also extract the year, month, day the same way
https://ruby-doc.org/stdlib-3.1.1/libdoc/date/rdoc/Date.html
a = [
'Thu, 17 Mar 2022 10:00:00.000000000 KST +09:00',
'Thu, 17 Mar 2022 10:00:00.000000000 KST +09:00',
'Thu, 17 Mar 2022 14:00:00.000000000 KST +09:00',
'Thu, 17 Mar 2022 14:00:00.000000000 KST +09:00',
'Thu, 17 Mar 2022 17:00:00.000000000 KST +09:00']
can_choose =[]
a.map do |time|
t = DateTime.parse(time)
can_choose << t.strftime("%k:%M")
end
p can_choose
=> ["10:00", "10:00", "14:00", "14:00", "17:00"]
Ruby is all about message passing. The syntax to send a message is:
receiver.message(argument)
strftime is such message, but it needs a proper receiver. So if you have some Time instance, e.g.:
time = Time.parse('2022-03-17 10:00:00 +0900')
you'd write:
time.strftime('%H:%M') #=> "10:00"
with time being the receiver, strftime being the message and '%H:%M' being the argument.
You can use the above code in an each loop like this:
can_choose = []
a.each do |time|
can_choose << time.strftime('%H:%M')
end
Or you could use map to convert your array to another array:
can_choose = a.map { |time| time.strftime('%H:%M') }
The curly braces here { ... } are equivalent to the do ... end block above.
I would simple go with:
can_choose = a.map { |datetime| datetime.strftime('%H:%M') }
If you need only hours and minutes in 24h format, just use %R directive with Time#strftime or DateTime#strftime
can_choose = a.map { |time| time.strftime('%R') }

Angular - Pushing elements into an array in a loop updates all the preexisting values of the array with the new value

I am pushing the dates of the week into an array.
If you can refer the code, in the // good value line
The array has the correct value
But each time the dates.setDate(dates.getDate() + 1 );
executes
All the array values are automatically updated with the new value.
Instead of just pushing the new element in the array, it pushes the new element in the array and replaces all the elements of the array with the new element
this.mondayDate = this.getMonday(this.viewDate);
let dates = this.mondayDate;
this.datesOfTheWeek = [];
this.datesOfTheWeek.push(this.mondayDate);
console.log(this.datesOfTheWeek);
for(let i in [1,2,3,4,5,6]){
console.log(this.datesOfTheWeek); // good value in the array
dates.setDate(dates.getDate() + 1 );
console.log(this.datesOfTheWeek); // bad value in the array
this.datesOfTheWeek.push(dates);
console.log(this.datesOfTheWeek);
}
console.log(this.datesOfTheWeek);
1st iteration: //contains only monday date- output from //bad value
Array(1) [Tue May 21 2019 15:17:46 GMT+0200 (heure d’été d’E…]
2nd iteration: // pushing tuesday date- output from //bad value
Array(2) [Wed May 22 2019 15:17:46 GMT+0200 (heure d’été d’E…, Wed May 22 2019 15:17:46 GMT+0200 (heure d’été d’E…]
The array value at the end is
Array(6) [Sun May 26 2019 15:17:46 GMT+0200 (heure d’été d’E…, Sun May 26 2019 15:17:46 GMT+0200 (heure d’été d’E…, Sun May 26 2019 15:17:46 GMT+0200 (heure d’été d’E…, Sun May 26 2019 15:17:46 GMT+0200 (heure d’été d’E…, Sun May 26 2019 15:17:46 GMT+0200 (heure d’été d’E…, Sun May 26 2019 15:17:46 GMT+0200 (heure d’été d’E…]
But it should contain the dates from may 20 to may 26
That's because dates looks to be a Date object, not a primitive (so, if you mutate it, all the references to it will point to the mutated value). You need to create a copy: instead of
dates.setDate(dates.getDate() + 1 );
console.log(this.datesOfTheWeek); // bad value in the array
this.datesOfTheWeek.push(dates);
do something like
let newDate = new Date(dates);
newDate.setDate(dates.getDate() + 1 );
console.log(this.datesOfTheWeek);
this.datesOfTheWeek.push(newDate);

how to sort json array by date field

I have a JSON list of 2-D data as
var data = [
[
'Sun Feb 05 2019 00:00:00 GMT+0530 (India Standard Time)',
2,
5
],
[
'Sun Feb 06 2019 00:00:00 GMT+0530 (India Standard Time)',
5,
10
],
[
'Sun Feb 04 2019 00:00:00 GMT+0530 (India Standard Time)',
6,
2
]
];
Where the first item of each array items is a date.
I have to sort this list by date so that Feb 04 will come first while Feb 06 will come last.
How can I sort this list in JSON?
Create a Date object then compare the milliseconds: new Date(date).getTime()
const data = [
['Sun Feb 05 2019 00:00:00 GMT+0530 (India Standard Time)', 2, 5],
['Sun Feb 06 2019 00:00:00 GMT+0530 (India Standard Time)', 5, 10],
['Sun Feb 04 2019 00:00:00 GMT+0530 (India Standard Time)', 6, 2]
];
data.sort((a, b) => {
return new Date(a[0]).getTime() - new Date(b[0]).getTime();
});
console.log(data);

Using Linux mktime to get timezone

I use the following codes to caculate timezone. When I set the timezone to Asia/Singapore, I think I should get 28800 which 28800/3600=8, it should be GMT +8, but it returns 27000/3600=7.5, Am I wrong?
struct tm tSysTime;
long int secs;
memset(&tSysTime,0,sizeof(tSysTime));
tSysTime.tm_year = 70;
tSysTime.tm_mon = 0;
tSysTime.tm_mday = 1;
tSysTime.tm_hour = 0;
tSysTime.tm_min = 0;
tSysTime.tm_sec = 0;
secs = 0-mktime(&tSysTime);
printf("[main] time zone %ld\n",secs);
Diagnosis
According to zdump -v Asia/Singapore on a Mac, the time zone offset from UTC for Singapore between August 1965 and January 1982 was 7h 30m east of UTC:
$ zdump -v Asia/Singapore
Asia/Singapore Fri Dec 13 20:45:52 1901 UTC = Sat Dec 14 03:41:17 1901 SMT isdst=0
Asia/Singapore Sat Dec 14 20:45:52 1901 UTC = Sun Dec 15 03:41:17 1901 SMT isdst=0
Asia/Singapore Wed May 31 17:04:34 1905 UTC = Wed May 31 23:59:59 1905 SMT isdst=0
Asia/Singapore Wed May 31 17:04:35 1905 UTC = Thu Jun 1 00:04:35 1905 MALT isdst=0
Asia/Singapore Sat Dec 31 16:59:59 1932 UTC = Sat Dec 31 23:59:59 1932 MALT isdst=0
Asia/Singapore Sat Dec 31 17:00:00 1932 UTC = Sun Jan 1 00:20:00 1933 MALST isdst=1
Asia/Singapore Tue Dec 31 16:39:59 1935 UTC = Tue Dec 31 23:59:59 1935 MALST isdst=1
Asia/Singapore Tue Dec 31 16:40:00 1935 UTC = Wed Jan 1 00:00:00 1936 MALT isdst=0
Asia/Singapore Sun Aug 31 16:39:59 1941 UTC = Sun Aug 31 23:59:59 1941 MALT isdst=0
Asia/Singapore Sun Aug 31 16:40:00 1941 UTC = Mon Sep 1 00:10:00 1941 MALT isdst=0
Asia/Singapore Sun Feb 15 16:29:59 1942 UTC = Sun Feb 15 23:59:59 1942 MALT isdst=0
Asia/Singapore Sun Feb 15 16:30:00 1942 UTC = Mon Feb 16 01:30:00 1942 JST isdst=0
Asia/Singapore Tue Sep 11 14:59:59 1945 UTC = Tue Sep 11 23:59:59 1945 JST isdst=0
Asia/Singapore Tue Sep 11 15:00:00 1945 UTC = Tue Sep 11 22:30:00 1945 MALT isdst=0
Asia/Singapore Sun Aug 8 16:29:59 1965 UTC = Sun Aug 8 23:59:59 1965 MALT isdst=0
Asia/Singapore Sun Aug 8 16:30:00 1965 UTC = Mon Aug 9 00:00:00 1965 SGT isdst=0
Asia/Singapore Thu Dec 31 16:29:59 1981 UTC = Thu Dec 31 23:59:59 1981 SGT isdst=0
Asia/Singapore Thu Dec 31 16:30:00 1981 UTC = Fri Jan 1 00:30:00 1982 SGT isdst=0
Asia/Singapore Mon Jan 18 03:14:07 2038 UTC = Mon Jan 18 11:14:07 2038 SGT isdst=0
Asia/Singapore Tue Jan 19 03:14:07 2038 UTC = Tue Jan 19 11:14:07 2038 SGT isdst=0
$
Consequently, the result you're getting is the correct offset from UTC in Singapore for 1970-01-01.
Subsidiary question
The current timezone of Singapore is GMT8. What I should do to fix this problem?
The current time zone offset of Singapore is UTC+8 (GMT+8), but historically (specifically, in 1970), that was not the case. You will have to devise a time nearer to the current time when the time zone offset in the database is correct. That seems to mean a time since 1982-01-01 00:30:00 +08:00. So, maybe you should use 2000-01-01 00:00:00? You'll need the number of seconds in the 30 years since 1970-01-01 00:00:00 to get the answer right, and you'll use that in place of the 0 in 0 - mktime(&tSysTime). I believe the relevant number is 946684800.
Revised C code
#include <stdio.h>
#include <string.h>
#include <time.h>
int main(void)
{
struct tm tSysTime;
long int secs;
memset(&tSysTime,0,sizeof(tSysTime));
tSysTime.tm_year = 100;
tSysTime.tm_mon = 0;
tSysTime.tm_mday = 1;
tSysTime.tm_hour = 0;
tSysTime.tm_min = 0;
tSysTime.tm_sec = 0;
secs = 946684800 - mktime(&tSysTime);
printf("[main] time zone %ld\n",secs);
return 0;
}
Example runs
$ TZ=Asia/Singapore tzoff
[main] time zone 28800
$ TZ=US/Pacific tzoff
[main] time zone -28800
$ TZ=UTC0 tzoff
[main] time zone 0
$
How did you find 946684800
That's a deep-seated mystery. No, it isn't. I have a pair of programs, strptime and timestamp that helped (plus a casual use of bc).
I live in the 'US/Pacific' (officially, America/Los_Angeles, but I don't like that name much — I live a lot closer to San Francisco) time zone (UTC-08:00 in the winter; UTC-07:00 during the summer).
$ strptime '2000-01-01 00:00:00'
946713600 = 2000-01-01 00:00:00
$ timestamp 946713600
946713600 = Sat Jan 01 00:00:00 2000
$ timestamp -Z 946713600
946713600 = Sat Jan 01 00:00:00 2000 -08:00
$ bc <<< '946713600 - 8 * 3600'
946684800
$ timestamp -Z 946684800
946684800 = Fri Dec 31 16:00:00 1999 -08:00
$ TZ=UTC0 timestamp -Z 946684800
946684800 = Sat Jan 01 00:00:00 2000 +00:00
$
If you spend the time working out how, you can probably do that with GNU date.

Using Arrays in Rabl

I am returning a collection from the query. The query is in this thread.
So my result is like below in my log:
[{"id"=>1, "name"=>"ASP.NET-WebForms", "description"=>"", "record_status"=>1, "created_by"=>1, "updated_by"=>1, "created_at"=>Thu, 23 Apr 2015 06:04:18 UTC +00:00, "updated_at"=>Thu, 23 Apr 2015 06:04:18 UTC +00:00, "skill_type"=>"Serverside-Framework", :assigned=>true}, {"id"=>2, "name"=>"ASP.NET-MVC", "description"=>"", "record_status"=>1, "created_by"=>1, "updated_by"=>1, "created_at"=>Thu, 23 Apr 2015 06:05:01 UTC +00:00, "updated_at"=>Thu, 23 Apr 2015 06:05:01 UTC +00:00, "skill_type"=>"Serverside-Framework", :assigned=>true}, {"id"=>3, "name"=>"RUBY-ON-RAILS", "description"=>"", "record_status"=>1, "created_by"=>1, "updated_by"=>1, "created_at"=>Thu, 23 Apr 2015 06:05:20 UTC +00:00, "updated_at"=>Thu, 23 Apr 2015 06:05:20 UTC +00:00, "skill_type"=>"Serverside-Framework", :assigned=>false}, {"id"=>4, "name"=>"C#", "description"=>"", "record_status"=>1, "created_by"=>1, "updated_by"=>2, "created_at"=>Thu, 23 Apr 2015 06:05:57 UTC +00:00, "updated_at"=>Thu, 23 Apr 2015 06:12:02 UTC +00:00, "skill_type"=>"Language", :assigned=>false}, {"id"=>5, "name"=>"Ruby", "description"=>"", "record_status"=>1, "created_by"=>1, "updated_by"=>1, "created_at"=>Thu, 23 Apr 2015 06:07:43 UTC +00:00, "updated_at"=>Thu, 23 Apr 2015 06:07:43 UTC +00:00, "skill_type"=>"Language", :assigned=>true}, {"id"=>6, "name"=>"VB", "description"=>"", "record_status"=>1, "created_by"=>1, "updated_by"=>1, "created_at"=>Thu, 23 Apr 2015 06:08:15 UTC +00:00, "updated_at"=>Thu, 23 Apr 2015 06:08:15 UTC +00:00, "skill_type"=>"Language", :assigned=>false}, {"id"=>7, "name"=>"SQL-Server", "description"=>"", "record_status"=>1, "created_by"=>1, "updated_by"=>1, "created_at"=>Thu, 23 Apr 2015 06:08:32 UTC +00:00, "updated_at"=>Thu, 23 Apr 2015 06:08:32 UTC +00:00, "skill_type"=>"DBMS", :assigned=>false}, {"id"=>8, "name"=>"MySQL", "description"=>"", "record_status"=>1, "created_by"=>1, "updated_by"=>1, "created_at"=>Thu, 23 Apr 2015 06:08:49 UTC +00:00, "updated_at"=>Thu, 23 Apr 2015 06:08:49 UTC +00:00, "skill_type"=>"DBMS", :assigned=>false}, {"id"=>9, "name"=>"Oracle", "description"=>"", "record_status"=>1, "created_by"=>1, "updated_by"=>1, "created_at"=>Thu, 23 Apr 2015 06:09:01 UTC +00:00, "updated_at"=>Thu, 23 Apr 2015 06:09:01 UTC +00:00, "skill_type"=>"DBMS", :assigned=>false}]
I think this is an array instead of an object collection. So how can I display this as json using rabl. The collection #technical_skills is not working.
My expected output is:
{
"domain_skill": {
"id": 1,
"name": "domain name",
"description": "some description text",
"technical_skills": [
{
"id": 1,
"name": "ASP.NET-WebForms",
"assigned": true
},
{
"id": 2,
"name": "ASP.NET-MVC",
"assigned": true
}
]
}
}
Edit:
I got that this is a json array. My method to merge another field so that I can convert this to json and merge the new fields. Now I thought this is json array. Please check my controller method below:
id = params[:id]
#domain_skill_technical_skill_ids = DomainSkillsTechnicalSkill.select('id, technical_skill_id').where(domain_skill_id: id).collect(&:technical_skill_id)
Rails.logger.info(#domain_skill_technical_skill_ids.to_a)
#technical_skills = []
TechnicalSkill.select('id, name').where(record_status: 1).each do |skill|
#technical_skills << skill.as_json.merge!(
{ assigned: #domain_skill_technical_skill_ids.include?(skill.id)}
)
end
#domain_skill_view_model = DomainSkillViewModel.new(#domain_skill, #technical_skills)
respond_with #domain_skill_view_model
My rabl:
object :#domain_skill_view_model
object :#domain_skill
attributes :id, :name, :description
node :technical_skills do
#technical_skills.each do |skill|
end
end

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