Converting an array of strings to an array of dateTimes - javascript

Beginner javascript learner here, trying to convert an array of strings to an array of dateTimes using just vanilla.
Sample input:
["2018-07-16T14:28:03.123",
"2018-07-20T14:00:27.123",
"2018-07-26T13:31:12.123",
"2018-08-12T13:03:37.123",
"2018-09-24T12:35:46.123"]
Wanted output:
[2018-07-16T14:28:03.123,
2018-07-20T14:00:27.123,
2018-07-26T13:31:12.123,
2018-08-12T13:03:37.123,
2018-09-24T12:35:46.123]
My string values are always dateTime string representations, so I've been trying to leverage new Date(stringDateTime) to convert each string to it's dateTime counterpart, but I'm running into trouble on how to navigate the array and build a new one with the appropriate dateTime data types.


Use the map function:
var datesStr = ["2018-07-16T14:28:03.123", "2018-07-20T14:00:27.123", "2018-07-26T13:31:12.123", "2018-08-12T13:03:37.123", "2018-09-24T12:35:46.123"]
var dates = datesStr.map(d => new Date(d));


While Igal's answer is more elegant and concise, I would try to show a more basic solution where you use a for loop and new Date():
var stringDates = ["2018-07-16T14:28:03.123",
"2018-07-20T14:00:27.123",
"2018-07-26T13:31:12.123",
"2018-08-12T13:03:37.123",
"2018-09-24T12:35:46.123"];
var dateObjects = [];
//Loop over your string array and push dates in your dateObjects array
for (var index in stringDates) {
var stringDate = stringDates[index];
dateObjects.push(new Date(stringDate));
}

Related

javascript - convert string to json array

I was using s3 select to fetch selective data and display them on my front end .
I converted array of byte to buffer and then to string like below as string
let dataString = Buffer.concat(records).toString('utf8');
the result i got was string like below
{"id":"1","obj1":"191.25","obj2":"11.81","obj3":"3.44","obj4":"15.62"}
{"id":"2","obj1":"642.00","obj2":"4.33","obj3":"0.00","obj4":"11.33"}
{"id":"3","obj1":"153.76","obj2":"94.77","obj3":"16.80","obj4":"29.79"}
{"id":"4","obj1":"61.71","obj2":"0.43","obj3":"0.00","obj4":"8.14"}
{"id":"5","obj1":"194.33","obj2":"108.89","obj3":"14.13","obj4":"168.60"}
{"id":"6","obj1":"204.31","obj2":"137.41","obj3":"34.76","obj4":"193.16"}
{"id":"7","obj1":"199.53","obj2":"34.53","obj3":"16.29","obj4":"26.56"}
{"id":"8","obj1":"77.33","obj2":"5.00","obj3":"12.50","obj4":"0.00"}
{"id":"9","obj1":"128.54","obj2":"101.60","obj3":"15.76","obj4":"46.23"}
{"id":"10","obj1":"107.00","obj2":"116.67","obj3":"34.42","obj4":"8.75"}
{"id":"12","obj1":"206.05","obj2":"155.03","obj3":"36.96","obj4":"148.99"}
{"id":"13","obj1":"133.93","obj2":"142.79","obj3":"39.91","obj4":"98.30"}
Now i want to convert them to json array , i got a solution like below
let dataArray = dataString.split('\n');
//remove white spaces and commas etc
dataArray = dataArray.filter(d=> d.length >2);
//change string to json
dataArray = dataArray.map(d=> JSON.parse(d));
Now the problem is that i have splitted them with new line and wont work if the json is compressed or data itself can have new line.
What is the best way to handle this situation. i want the output like below
[{"id":"1","obj1":"191.25","obj2":"11.81","obj3":"3.44","obj4":"15.62"},
{"id":"2","obj1":"642.00","obj2":"4.33","obj3":"0.00","obj4":"11.33"},
{"id":"3","obj1":"153.76","obj2":"94.77","obj3":"16.80","obj4":"29.79"},
{"id":"4","obj1":"61.71","obj2":"0.43","obj3":"0.00","obj4":"8.14"},
{"id":"5","obj1":"194.33","obj2":"108.89","obj3":"14.13","obj4":"168.60"},
{"id":"6","obj1":"204.31","obj2":"137.41","obj3":"34.76","obj4":"193.16"},
{"id":"7","obj1":"199.53","obj2":"34.53","obj3":"16.29","obj4":"26.56"},
{"id":"8","obj1":"77.33","obj2":"5.00","obj3":"12.50","obj4":"0.00"},
{"id":"9","obj1":"128.54","obj2":"101.60","obj3":"15.76","obj4":"46.23"},
{"id":"10","obj1":"107.00","obj2":"116.67","obj3":"34.42","obj4":"8.75"},
{"id":"12","obj1":"206.05","obj2":"155.03","obj3":"36.96","obj4":"148.99"},
{"id":"13","obj1":"133.93","obj2":"142.79","obj3":"39.91","obj4":"98.30"}
]

#sumit
please take a look at this solution.
let dataString=`{"id":"1","obj1":"191.25","obj2":"11.81","obj3":"3.44","obj4":"15.62"}
{"id":"2","obj1":"642.00","obj2":"4.33","obj3":"0.00","obj4":"11.33"}
{"id":"3","obj1":"153.76","obj2":"94.77","obj3":"16.80","obj4":"29.79"}
{"id":"4","obj1":"61.71","obj2":"0.43","obj3":"0.00","obj4":"8.14"}
{"id":"5","obj1":"194.33","obj2":"108.89","obj3":"14.13","obj4":"168.60"}
{"id":"6","obj1":"204.31","obj2":"137.41","obj3":"34.76","obj4":"193.16"}
{"id":"7","obj1":"199.53","obj2":"34.53","obj3":"16.29","obj4":"26.56"}
{"id":"8","obj1":"77.33","obj2":"5.00","obj3":"12.50","obj4":"0.00"}
{"id":"9","obj1":"128.54","obj2":"101.60","obj3":"15.76","obj4":"46.23"}
{"id":"10","obj1":"107.00","obj2":"116.67","obj3":"34.42","obj4":"8.75"}
{"id":"12","obj1":"206.05","obj2":"155.03","obj3":"36.96","obj4":"148.99"}
{"id":"13","obj1":"133.93","obj2":"142.79","obj3":"39.91","obj4":"98.30"}`;
let dataArray = dataString.match(/{(?:[^{}]*|(R))*}/g);
dataArray = dataArray.map(d=> JSON.parse(d));
console.log(dataArray);

Yeah, it is not a very good idea to concatenate objects into a string like that. If you don't have any other choice, however, something like that should do the trick:
const initialString = `{"id":"1","obj1":"191.25","obj2":"11.81","obj3":"3.44","obj4":"15.62"}
{"id":"2","obj1":"642.00","obj2":"4.33","obj3":"0.00","obj4":"11.33"}
{"id":"3","obj1":"153.76","obj2":"94.77","obj3":"16.80","obj4":"29.79"}
{"id":"4","obj1":"61.71","obj2":"0.43","obj3":"0.00","obj4":"8.14"}
{"id":"5","obj1":"194.33","obj2":"108.89","obj3":"14.13","obj4":"168.60"}
{"id":"6","obj1":"204.31","obj2":"137.41","obj3":"34.76","obj4":"193.16"}
{"id":"7","obj1":"199.53","obj2":"34.53","obj3":"16.29","obj4":"26.56"}
{"id":"8","obj1":"77.33","obj2":"5.00","obj3":"12.50","obj4":"0.00"}
{"id":"9","obj1":"128.54","obj2":"101.60","obj3":"15.76","obj4":"46.23"}
{"id":"10","obj1":"107.00","obj2":"116.67","obj3":"34.42","obj4":"8.75"}
{"id":"12","obj1":"206.05","obj2":"155.03","obj3":"36.96","obj4":"148.99"}
{"id":"13","obj1":"133.93","obj2":"142.79","obj3":"39.91","obj4":"98.30"}`;
const json = `[${initialString.replace(/}\s*{/g, '},{')}]`;
const array = JSON.parse(json);

JSON to JS array

JSON:
[{"CDATE":"0000-00-00","DISTANCE":"0"},
{"CDATE":"0000-00-00","DISTANCE":"1"},
{"CDATE":"0000-00-00","DISTANCE":"2"},
{"CDATE":"0000-00-00","DISTANCE":"3"}]
Is it possible to put all the distance value in their own array in JS? The formatting will be consistent as it comes from an API and is always formatted correctly.
What I've tried:
var arry = [ /* JSON noted above */ ];
alert(arry[1])
and
var arry = JSON.parse([ /* JSON noted above */ ]);
alert(arry[1])
Expected:
1
Actual:
{"CDATE":"0000-00-00","DISTANCE":"1"}
and the other gives an error.
I would like to extract just the DISTANCE value as an array of DISTANCE
I've tried JSON.parse() but I don't think this is what I am after as it hasn't worked for me.

Use .map
var data = [{"CDATE":"0000-00-00","DISTANCE":"0"},
{"CDATE":"0000-00-00","DISTANCE":"1"},
{"CDATE":"0000-00-00","DISTANCE":"2"},
{"CDATE":"0000-00-00","DISTANCE":"3"}];
var distance = data.map(el => el.DISTANCE);
console.log(distance[2]);
console.log(distance);
It is already a valid json so you do not need to use JSON.parse()

JavaScript return object property value

I have this object:
{"Header":["Date","Test1","Test2","Test3","N/A","Test4","Test5"],
"Values":[["Total Unique","79 280","1 598","5 972","20","2 633","9 696"],
["2017-06-19","28 026","1 036","3 667","20","1 097","4 672"]]}
My desired result is this:
Date
2017-06-19
What I was able to achieve:
Date ["2017-06-19","28 026","1 036","3 667","20","1 097","4 672"]
Using this code:
vm.header = data.Header[0];
vm.data1 = data.Values[1];

Because data.Values is a two-dimensional array you can get the desired result by changing the code to:
vm.header = data.Header[0];
vm.data1 = data.Values[1][0];

Header[0] = 'Date';
Header[1]= 'Test1';
Header[2]= 'Test2';
Header[3]= 'Test3';
Header[4]= 'N/A';
Header[5]= 'Test4';
Header[6]= 'Test5';
Values is 2D array
Values[0] = ["Total Unique","79 280","1 598","5 972","20","2 633","9 696"]
Values[1]=["2017-06-19","28 026","1 036","3 667","20","1 097","4 672"]
What you have tried so far is data.Header[0] would give you 'Date'. data.Values[1] would give you whole array. So you need to get "2017-06-19" you have to get first element of that array ie data.Values[1][0]

Javascript: divide object date value per day

Hi Everyone,
I have this object:
{"2017-07-09 00:00:00":4,"2017-07-09 09:00:00":1,"2017-07-09 10:00:00":4,"2017-07-09 11:00:00":3,"2017-07-09 12:00:00":16,"2017-07-09 13:00:00":4,"2017-07-09 14:00:00":6,"2017-07-09 15:00:00":5,"2017-07-09 16:00:00":7,"2017-07-09 17:00:00":21,"2017-07-09 18:00:00":25,"2017-07-09 19:00:00":1,"2017-07-10 09:00:00":11,"2017-07-10 10:00:00":4,"2017-07-10 11:00:00":21,"2017-07-10 12:00:00":22,"2017-07-10 13:00:00":23,"2017-07-10 14:00:00":42,"2017-07-10 15:00:00":14,"2017-07-10 16:00:00":36,"2017-07-10 17:00:00":21,"2017-07-10 18:00:00":5,"2017-07-11 09:00:00":16,"2017-07-11 10:00:00":7,"2017-07-11 11:00:00":26,"2017-07-11 12:00:00":34,"2017-07-11 13:00:00":39,"2017-07-11 14:00:00":39,"2017-07-11 15:00:00":30,"2017-07-11 16:00:00":33,"2017-07-11 17:00:00":22,"2017-07-11 18:00:00":1}
I'm trying to divide it per day and get something like this:
First create an array for the day which is 24 hours:
[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23]
And than calculate how many day is in the object above and get a value for each hours and return something like below. In the object I have 3 days, so I need to return 3 arrays for each days:
[4,0,0,0,0,0,0,0,0,1,10,3,16,...],
[0,0,0,0,0,0,0,0,0,11,4,21,22,23,42,...]
[0,0,0,0,0,0,0,0,0,16,7,26,34,39,39,30,..]
For each hours which is not in the object data return 0 and for each hours that exist return the specified value on the object.
for example on the object the time starts from "2017-07-09 00:00:00":4 and it has the value of 4 and for each hours between that and "2017-07-09 09:00:00":1
return 0.
Any help appreciated. Thanks a lot for your time

You have first to loop into each keys of your object.
After that many solutions, one is to convert your keys into Date object and compare the hour of your object in a for loop.
And retrieve the right data by reconverting your Date obj into your obj property.
Edit
Access your property value without function by using Object.keys and findIndex
I've maybe misunderstand your requirement, but you've a good example
of how to do ;-)
Example of solution
var data ={"2017-07-09 00:00:00":4,"2017-07-09 09:00:00":1,"2017-07-09 10:00:00":4,"2017-07-09 11:00:00":3,"2017-07-09 12:00:00":16,"2017-07-09 13:00:00":4,"2017-07-09 14:00:00":6,"2017-07-09 15:00:00":5,"2017-07-09 16:00:00":7,"2017-07-09 17:00:00":21,"2017-07-09 18:00:00":25,"2017-07-09 19:00:00":1,"2017-07-10 09:00:00":11,"2017-07-10 10:00:00":4,"2017-07-10 11:00:00":21,"2017-07-10 12:00:00":22,"2017-07-10 13:00:00":23,"2017-07-10 14:00:00":42,"2017-07-10 15:00:00":14,"2017-07-10 16:00:00":36,"2017-07-10 17:00:00":21,"2017-07-10 18:00:00":5,"2017-07-11 09:00:00":16,"2017-07-11 10:00:00":7,"2017-07-11 11:00:00":26,"2017-07-11 12:00:00":34,"2017-07-11 13:00:00":39,"2017-07-11 14:00:00":39,"2017-07-11 15:00:00":30,"2017-07-11 16:00:00":33,"2017-07-11 17:00:00":22,"2017-07-11 18:00:00":1}
var dataKeys = Object.keys(data);
var dataKeysParsed = dataKeys.map(function(d){
return new Date(d);
});
var res =[];
for (var i=0;i<=23;i++){
var id = dataKeysParsed.findIndex(function(k){
return k.getHours() == i
});
res.push(id > -1 ? data[dataKeys[id]] : 0);
}
console.log(res);

How to calculate two values from bracket in javascript

I am creating geofencing featured website. So I need to calculate some expression. I have two values related to latitude and longitude.
for e.g: var value = '(41.878113,-87.629798)'
How to separate above two values in javascript

The Google Maps LatLng API provides .lat() and .lng() functions for accessing them individually. You can use them like this:
var coords = new google.maps.LatLng(42.878113,-87.629798);
console.log(coords.lat()); // 42.878113
console.log(coords.lng()); // -87.629798

That's not valid JavaScript. (Post was edited, it wasn't valid at first)
One method you could do is define it as an array:
var cords = [41.878113, -87.629798];
From here you could reference it like so:
cords[0]; // Out: 41.878113
cords[1]; // Out: -87.629798

An easy way would be to separate the string at the , then remove non-numeric characters
var value = '(41.878113,-87.629798)';
var parts = value.split(',');
//=> ["(41.878113", "-87.629798)"]
var lat = parts[0].replace(/[^\d.-]/g, '');
//=> "41.878113"
var lng = parts[1].replace(/[^\d.-]/g, '');
//=> "-87.629798"
Now you can use them in some sort of calculation
calculateSomething(lat, lng);
Which would be the same as
calculateSomething("41.878113", "-87.629798");

If value is a String that is always in that format and you want an Array that contains the 2 values in String format , this example should suffice
var value = '(41.878113,-87.629798)';
document.getElementById('out').textContent = JSON.stringify(value.slice(1, -1).split(','), null, 2);
<pre id="out"></pre>

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