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Extract specific digits from a .txt file

I have been asked to count the number of tweets per hour by day (0 - 23) in a huge text file of random tweets. The date is not interesting, only the tweet per hour. I want to return them in a new array of objects. Each object should have properties hour and count like this:
{hour: x, count: y},
I've made a function where I'm declaring an empty array, in which I will put my data:
function(tweets) {
let result = [];
and I think I need to push them like this:
result.push({hour: x, count: y});
But I don't know how to extract the specific hour from my object (key and value).
in the huge, raw data file, each tweet is logged with a date like this:
created_at: "30-06-2015 14:27",
Any suggestions or experience? I'm currently learning about regex and for loops. Should I use them in this code or is there a smarter way?
Edit: as you asked for more details:
The raw data are object in an array with the following structure:
{
time: Date-object,
created_at: "30-06-2015 14:27",
fromUsername: "victor",
text: "asyl og integration",
lang: "da",
source: "Twitter for Android",
}

About extracting text I see good answer here. Instead of console.log add parsing and saving to your array.
About regexp - I think it should be something like
var re = /created_at: \"([^\"]*)\",/g;

What I would do is work from a different angle:
create an object with a dateTimeHour for the start of each hour that you care about. It should presumably be a limited timespan like for all tweets that happened before now:
So generate something that looks like this dynamically:
{
'2019-03-01T17:22:30Z': 0, // or simply '1552667443928'
'2019-03-01T18:22:30Z': 0,
'2019-03-01T19:22:30Z': 0,
'2019-03-01T20:22:30Z': 0,
...etc
}
Which you can do using current Date and then a loop to create additional previous date times:
const now = new Date()
// you can use a generator here or simply a while loop:
const dateTimes = {}
while(now > REQUIRED_DATE)
dateTimes[new Date(now.setHours(now.getHours() - 1))] = 0
Now you have an exhausted list of all the hours.
Then, check if the given tweet is within that hour:
check if item.created_at < currentHourBeingLooked because you should loop through the Object.keys(dateTimes).
Then, loop through each item in your list and check if it fits that dateTime if so increment dateTimes[currentHour]++.
So, the hardest part will be converting created_at to a normal looking date time string:
const [datePortion, timePortion] = "30-06-2015 14:27".split(' ')
const [day, month, year] = datePortion.split('-')
const [hour, minute] = timePortion.split(':')
now with all those date, month, year, hour, and minute you can build a time object in javascript:
It follows the formula:
From MDN:
new Date(year, monthIndex [, day [, hours [, minutes [, seconds [, milliseconds]]]]]);
AKA:
new Date(year, monthIndex, day, hours, minutes, seconds);
So for December 17, 2019 # 3:24am it'll be:
const = new Date(2019, 11, 17, 3, 24, 0);

I'll assume that you already know to use regex from the post pointed by Ralkov to get all of your created_at dates, and my answer will go from that.
You said the date is not important so once you have the string
'created_at: "30-06-2015 14:27"'
we need to get rid of everything except for the hour, i did it by extracting substrings, feel free to try other approaches, this is just to get you started.
var date = obj.substr(obj.indexOf(' ') + 1);
var time = date.substr(date.indexOf(' ') + 1);
var hour = time.substr(0, time.indexOf(':'));
will get yo the hour
"14"
Note that this only works for one day, you need to do some additional changes if you'd like to store tweet hour count for different days in the same data structure
When you write your for-loop use the following function each time you find a tweet and already extracted the hour, it stores a combination of value-pairs into a map variable defined outside the function, creating a new pair if necessary or just updates it with the new tweet count.
function newTweet(hour, tweetsPerHour) {
var tweetsThisHour = tweetsPerHour.get(hour);
tweetsThisHour = tweetsThisHour === undefined ? 0 : tweetsThisHour;
tweetsPerHour.set(hour, ++tweetsThisHour);
console.log(tweetsThisHour)
}
complete code:
var obj = 'created_at: "30-06-2015 14:27"';
var date = obj.substr(obj.indexOf(' ')+1);
var time = date.substr(date.indexOf(' ')+1);
var hour = time.substr(0, time.indexOf(':'));
var tweetsPerHour = new Map();
newTweet(hour, tweetsPerHour); //this is the extracted hour
newTweet("16", tweetsPerHour); //you can try different hours as well
newTweet("17", tweetsPerHour);
function newTweet(hour, tweetsPerHour) {
var tweetsThisHour = tweetsPerHour.get(hour);
tweetsThisHour = tweetsThisHour === undefined ? 0 : tweetsThisHour;
tweetsPerHour.set(hour, ++tweetsThisHour);
console.log(hour + " tweet count: " + tweetsThisHour)
}
what the code is doing is storing the hour and count of tweets in pairs:
[{"14":1} ,{"16":1}, {17:1}]
for example if you add "14" again it would update to
[{"14":2}, {"16":1}, {17:1}]
dig into JavaScript Map Objects as well.
Your code flow is something like the following:
Read .txt file
loop through dates -> get hour from date -> newTweet(hour,
tweetsPerHour).

Showing next available dates with 24h margin with Angular and MomentJS

I'm trying to display an array of possible delivery dates using AngularJS and MomentJS.
The issue is that it needs to meet certain conditions: Delivery dates are only Monday, Wednesday and Fridays.
Also, when the page loads, it recognizes the current date and it will only display the next available date that is minimum 24h away (e.g., if I load the page on a Sunday at 1pm, the first available date will be Wednesday, as Monday doesn't meet the 24h margin).
So far I could only think if dealing with the issue doing conditionals for every day of the week, but I'm pretty sure there has to be a neater way of dealing with it.
Here's what I did so far:
$scope.today = moment();
$scope.$watch('today', function () {
if ($scope.today = moment().day('Sunday')){
$scope.nextdateone = moment().add(3, 'd');
$scope.nextdatetwo = moment().add(5, 'd');
$scope.nextdatethree = moment().add(8, 'd');
$scope.nextdatefour = moment().add(10, 'd');
}
else if ($scope.today = moment().day('Monday')){
$scope.nextdateone = moment().add(2, 'd');
$scope.nextdatetwo = moment().add(4, 'd');
$scope.nextdatethree = moment().add(7, 'd');
$scope.nextdatefour = moment().add(9, 'd');
}
else if ...
});
This was the logic I came up with, but it doesn't really work as of now...
Any tips?

The delivery dates "Monday, Wednesday and Fridays", which (according to http://momentjs.com/docs/#/get-set/day/) you can represent as 1, 3 and 5.
So I would create a array with those dates, and then given the current day I would iterate that array of delivery dates to find the most suitable one... something like this:
const deliveryDates = [1, 3, 5];
const getDeliveryDate = (today) => {
let deliveryIndex = -1;
deliveryDates.some((date, index) => {
// If today is a delivery date, then schedule for the next delivery
if (today === date) {
deliveryIndex = index + 1;
return true;
}
// If today is before the current delivery date, store it
if (today < date) {
deliveryIndex = index;
return true;
}
});
// If delivery date is out of bounds, return the first delivery date
return deliveryIndex === deliveryDates.length || deliveryIndex === -1 ? 0 : deliveryIndex;
};
const getNextDelivery = (today) => {
return deliveryDates[getDeliveryDate(today)];
};
console.log(moment().day(getNextDelivery(moment().day())));
You can check a working example here:
https://jsbin.com/jawexafiji/edit?js,console

I can't seem to compare two date objects. One from mongo, one generated

edit, I've been able to work around this problem by comparing the values of the dates rather than the dates themselves:
$scope.entries[0].formattedDate === $scope.days[0]
$scope.entries[i].formattedDate.valueOf() === $scope.days[0].valueOf() //true
The goal of this angularjs program is to:
Generate the days in the current week (as an array of Javascript Date Objects)
Obtain a bunch of JSON objects from mongodb. (These objects have a property called "date." This "date" property is in the following format: ISODate("2016-05-18T04:44:42.067Z")
Compare each of the mongo items to a generated day, tell the user if any match (only the day! disregard time)
This is my code to generate the days of the week, and it works well:
$scope.getWeek = function (num) {
var curr = new Date;
curr.setDate(curr.getDate() - (num * 7));
var days = [];
for (var i = 0; i < 7; i++) {
days.push(new Date(curr.setDate(curr.getDate() - curr.getDay() + i)));
days[i].setHours(0, 0, 0, 0);
}
$scope.days = days;
};
I only want to know if the day matches, and not the time. I am using this function to strip the time from every item retrieved from Mongodb:
var removeHours = function (date) {
date.setHours(0, 0, 0, 0);
return date;
};
When it comes to comparing the dates, I'm absolutely stuck! It seems like I've tried everything. When I console.log the two dates, they are identical. I'm probably not aware of something about JS objects and I'm hoping somebody can provide a simple, easy solution.
$scope.entries[i].formattedDate == $scope.days[0] // false

Find next instance of a given weekday (ie. Monday) with moment.js

I want to get the date of the next Monday or Thursday (or today if it is Mon or Thurs). As Moment.js works within the bounds of a Sunday - Saturday, I'm having to work out the current day and calculate the next Monday or Thursday based on that:
if (moment().format("dddd")=="Sunday") { var nextDay = moment().day(1); }
if (moment().format("dddd")=="Monday") { var nextDay = moment().day(1); }
if (moment().format("dddd")=="Tuesday") { var nextDay = moment().day(4); }
if (moment().format("dddd")=="Wednesday") { var nextDay = moment().day(4); }
if (moment().format("dddd")=="Thursday") { var nextDay = moment().day(4); }
if (moment().format("dddd")=="Friday") { var nextDay = moment(.day(8); }
if (moment().format("dddd")=="Saturday") { var nextDay = moment().day(8); }
This works, but surely there's a better way!

The trick here isn't in using Moment to go to a particular day from today. It's generalizing it, so you can use it with any day, regardless of where you are in the week.
First you need to know where you are in the week: moment().day(), or the slightly more predictable (in spite of locale) moment().isoWeekday(). Critically, these methods return an integer, which makes it easy to use comparison operators to determine where you are in the week, relative to your targets.
Use that to know if today's day is smaller or bigger than the day you want. If it's smaller/equal, you can simply use this week's instance of Monday or Thursday...
const dayINeed = 4; // for Thursday
const today = moment().isoWeekday();
if (today <= dayINeed) {
return moment().isoWeekday(dayINeed);
}
But, if today is bigger than the day we want, you want to use the same day of next week: "the monday of next week", regardless of where you are in the current week. In a nutshell, you want to first go into next week, using moment().add(1, 'weeks'). Once you're in next week, you can select the day you want, using moment().day(1).
Together:
const dayINeed = 4; // for Thursday
const today = moment().isoWeekday();
// if we haven't yet passed the day of the week that I need:
if (today <= dayINeed) {
// then just give me this week's instance of that day
return moment().isoWeekday(dayINeed);
} else {
// otherwise, give me *next week's* instance of that same day
return moment().add(1, 'weeks').isoWeekday(dayINeed);
}
See also https://stackoverflow.com/a/27305748/800457
EDIT: other commenters have pointed out that the OP wanted something more specific than this: the next of an array of values ("the next Monday or Thursday"), not merely the next instance of some arbitrary day. OK, cool.
The general solution is the beginning of the total solution. Instead of comparing for a single day, we're comparing to an array of days: [1,4]:
const daysINeed = [1,4]; // Monday, Thursday
// we will assume the days are in order for this demo, but inputs should be sanitized and sorted
function isThisInFuture(targetDayNum) {
// param: positive integer for weekday
// returns: matching moment or false
const todayNum = moment().isoWeekday();
if (todayNum <= targetDayNum) {
return moment().isoWeekday(targetDayNum);
}
return false;
}
function findNextInstanceInDaysArray(daysArray) {
// iterate the array of days and find all possible matches
const tests = daysINeed.map(isThisInFuture);
// select the first matching day of this week, ignoring subsequent ones, by finding the first moment object
const thisWeek = tests.find((sample) => {return sample instanceof moment});
// but if there are none, we'll return the first valid day of next week (again, assuming the days are sorted)
return thisWeek || moment().add(1, 'weeks').isoWeekday(daysINeed[0]);;
}
findNextInstanceInDaysArray(daysINeed);
I'll note that some later posters provided a very lean solution that hard-codes an array of valid numeric values. If you always expect to search the same days, and don't need to generalize for other searches, that'll be the more computationally efficient solution, although not the easiest to read, and impossible to extend.

get the next monday using moment
moment().startOf('isoWeek').add(1, 'week');

moment().day() will give you a number referring to the day_of_week.
What's even better: moment().day(1 + 7) and moment().day(4 + 7) will give you next Monday, next Thursday respectively.
See more: http://momentjs.com/docs/#/get-set/day/

The following can be used to get any next weekday date from now (or any date)
var weekDayToFind = moment().day('Monday').weekday(); //change to searched day name
var searchDate = moment(); //now or change to any date
while (searchDate.weekday() !== weekDayToFind){
searchDate.add(1, 'day');
}

Most of these answers do not address the OP's question. Andrejs Kuzmins' is the best, but I would improve on it a little more so the algorithm accounts for locale.
var nextMoOrTh = moment().isoWeekday([1,4,4,4,8,8,8][moment().isoWeekday()-1]);

Here's a solution to find the next Monday, or today if it is Monday:
const dayOfWeek = moment().day('monday').hour(0).minute(0).second(0);
const endOfToday = moment().hour(23).minute(59).second(59);
if(dayOfWeek.isBefore(endOfToday)) {
dayOfWeek.add(1, 'weeks');
}

Next Monday or any other day
moment().startOf('isoWeek').add(1, 'week').day("monday");

IMHO more elegant way:
var setDays = [ 1, 1, 4, 4, 4, 8, 8 ],
nextDay = moment().day( setDays[moment().day()] );

Here's e.g. next Monday:
var chosenWeekday = 1 // Monday
var nextChosenWeekday = chosenWeekday < moment().weekday() ? moment().weekday(chosenWeekday + 7) : moment().weekday(chosenWeekday)

The idea is similar to the one of XML, but avoids the if / else statement by simply adding the missing days to the current day.
const desiredWeekday = 4; // Thursday
const currentWeekday = moment().isoWeekday();
const missingDays = ((desiredWeekday - currentWeekday) + 7) % 7;
const nextThursday = moment().add(missingDays, "days");
We only go "to the future" by ensuring that the days added are between 0 and 6.

In Moment.js, how do you get the current financial Quarter?

Is there a simple/built in way of figuring out the current financial quarter?
ex:
Jan-Mar: 1st
Apr-Jul: 2nd
Jul-Sept: 3rd
Oct-Dec: 4th

This is now supported in moment:
moment('2014-12-01').utc().quarter() //outputs 4
moment().quarter(); //outputs current quarter ie. 2
Documentation

Using version 2.14.1+ you can do something like the following:
moment().quarter() returns the current quarter number: 1, 2, 3, 4.
moment().quarter(moment().quarter()).startOf('quarter');
Would return the current quarter with the date set to the quarter starting date.
moment().quarter(moment().quarter()).startOf('quarter');
Would return the current quarter with the date set to quarter ending date.
You could also define a function that takes the corresponding quarter number as argument (1,2,3,4), and returns an object containing the start and end date of the quarter.
function getQuarterRange(quarter) {
const start = moment().quarter(quarter).startOf('quarter');
const end = moment().quarter(quarter).endOf('quarter');
return {start, end};
}

Use this simple code to get all quarter based on january and april
Demo
Code :
// startMonth should be january or april
function setQuarter(startMonth) {
var obj = {};
if(startMonth=='january'){
obj.quarter1 = {start:moment().month(0).startOf('month'),end:moment().month(2).endOf('month')}
obj.quarter2 = {start:moment().month(3).startOf('month'),end:moment().month(5).endOf('month')}
obj.quarter3 = {start:moment().month(6).startOf('month'),end:moment().month(8).endOf('month')}
obj.quarter4 = {start:moment().month(9).startOf('month'),end:moment().month(11).endOf('month')}
console.log(obj);
return obj;
}
else if(startMonth=='april'){
obj.quarter1 = {start:moment().month(3).startOf('month'),end:moment().month(5).endOf('month')}
obj.quarter2 = {start:moment().month(6).startOf('month'),end:moment().month(8).endOf('month')}
obj.quarter3 = {start:moment().month(9).startOf('month'),end:moment().month(11).endOf('month')}
obj.quarter4 = {start:moment().month(0).startOf('month').add('years',1),end:moment().month(2).endOf('month').add('years',1)}
console.log(obj);
return obj;
}
}
setQuarter('april');
Fiddle

START DATE
moment().quarter(moment().quarter()).startOf('quarter');
Would return the current quarter with the date set to the quarter starting date.
moment("2019", "YYYY").quarter(4).startOf('quarter');
Would return the starting date of the 4th quarter of the year "2019".
moment().startOf('quarter');
Would return the starting date of the current quarter of current year.
END DATE
moment().quarter(moment().quarter()).endOf('quarter');
Would return the current quarter with the date set to quarter ending date.
moment("2019", "YYYY").quarter(4).endOf('quarter');
Would return the ending date of the 4th quarter of the year "2019".
moment().endOf('quarter');
Would return the ending date of the current quarter of current year.

I dont think any of these answers explain how to get the financial quarter. They explain how to get the calendar quarter.
I do not have a clean answer as thats what led me here. But the fiscal quarter is what is really wanted. And that is based on the start month of the fiscal year.
For example if my company's fiscal start month is February. Then at the time of writing this January 9th 2017 I'm actually in Q4 2016.
To accomplish this we need a way to get the quarter relative to a supplied integer of the start month.

There is nothing built in right now, but there is conversation to add formatting tokens for quarters. https://github.com/timrwood/moment/pull/540
In the meantime, you could use something like the following.
Math.floor(moment().month() / 3) + 1;
Or, if you want it on the moment prototype, do this.
moment.fn.quarter = function () {
return Math.floor(this.month() / 3) + 1;
}

The formula that seems to work for me is:
Math.ceil((moment().month() + 1) / 3);
moment().month() gives back the 0-11 month format so we have to add one
THE ACTUAL MONTH = (moment().month() + 1)
then we have to divide by 3 since there are 3 months in a quarter.
HOW MANY QUARTERS PASSED = (THE ACTUAL MONTH) / 3
and then we have to get the ceiling of that (round to the nearest quarter end)
CEILING(HOW MANY QUARTERS PASSED)
EDIT:
The Official formula (not commited yet) is:
~~((this.month()) / 3) + 1;
which means Math.floor((this.month()) / 3) + 1;

The simplist way to do this is
Math.floor(moment.month() / 3)
That will give you the zero based quarter index. ie 0, 1, 2, or 3.
Then, if you want the quarter's literal number, just add one.

Answer given by Nishchit Dhanani, is correct but has one issue in 'April' scenario.
Issue: If your financial year is April than, For first 3 months i.e. JAN, FEB & MAR
obj.quarter1.start date returns, 1-April-CurrentYear [incorrect Value]
obj.quarter4.end date retunrs, 31-March-NextYear [incorrect Value]
Correct values should be,
Start = 1-April-PreviuosYear
End = 31-March-CurrentYear
So, Taking consideration for first 3 month it can be written something like,
const obj = {};
/* 0-Jan, 1-Feb, 2-Mar */
if (moment().month() <= 2) {
obj.quarter1 = { start: moment().month(3).startOf('month').add('years', -1), end: moment().month(5).endOf('month').add('years', -1) };
obj.quarter2 = { start: moment().month(6).startOf('month').add('years', -1), end: moment().month(8).endOf('month').add('years', -1) };
obj.quarter3 = { start: moment().month(9).startOf('month').add('years', -1), end: moment().month(11).endOf('month').add('years', -1) };
obj.quarter4 = { start: moment().month(0).startOf('month'), end: moment().month(2).endOf('month') };
} else {
obj.quarter1 = { start: moment().month(3).startOf('month'), end: moment().month(5).endOf('month') };
obj.quarter2 = { start: moment().month(6).startOf('month'), end: moment().month(8).endOf('month') };
obj.quarter3 = { start: moment().month(9).startOf('month'), end: moment().month(11).endOf('month') };
obj.quarter4 = { start: moment().month(0).startOf('month').add('years', 1), end: moment().month(2).endOf('month').add('years', 1) };
}
console.log(obj);