Javascript/jQuery get previous array value from each loop

Question

I have these data array dataTimeName

{"imsak":"04:44","fajr":"04:54","sunrise":"06:15","dhuhr":"12:17","asr":"15:40","maghrib":"18:19","isha":"19:31"}

and the JS

$.each(dataTimeName,function(key, val)
{
    var current = "15:40";
    var previousArray = ""; //<-- how to get the previous from current?
});

My question is how to get the previous value from the current 15:40 from dataTimeName list?
It means, I will get previous value before 15:40 is 12:17.

var dataTimeName  = {"imsak":"04:44","fajr":"04:54","sunrise":"06:15","dhuhr":"12:17","asr":"15:40","maghrib":"18:19","isha":"19:31"};

$.each(dataTimeName,function(key, val)
{
  var current = "15:40";
  var previousArray = ""; //<-- how to get the previous from current?
  alert(val);
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

Maybe array makes sense to have this order. You can convert your object times into an array and then access the previous time. — Hassan Imam
– Hassan Imam, Commented Jan 30, 2021 at 9:02
Maybe something like this [ "04:44", "04:54", "06:15", "12:17", "15:40", "18:19", "19:31" ] — Hassan Imam
– Hassan Imam, Commented Jan 30, 2021 at 9:12

Swati · Accepted Answer · 2021-01-31 13:59:38Z

1

You can add your JSON values inside some array and use .findIndex() to get index of current(which is search) then just subtract -1 and access previous value.

Demo Code :

var dataTimeName = {
  "imsak": "04:44",
  "fajr": "04:54",
  "sunrise": "06:15",
  "dhuhr": "12:17",
  "asr": "15:40",
  "maghrib": "18:19",
  "isha": "19:31"
};
var currents = "15:40";
var ids = []
$.each(dataTimeName, function(key, val) {
  ids.push(val);//push values inside array
});
console.log(ids)
//find index where value matches - 1 (to get previous value)
var position = ids.findIndex(x => x === currents) - 1
console.log(ids[position])//access value like this

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

answered Jan 31, 2021 at 13:59

Swati

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Comments

Vahid Alimohamadi · Accepted Answer · 2021-01-31 14:29:13Z

1

You have a sorted array so you can access it's previous index:

let dataTimeName  = {"imsak":"04:44","fajr":"04:54","sunrise":"06:15","dhuhr":"12:17","asr":"15:40","maghrib":"18:19","isha":"19:31"};

let current = "15:40"

// sorted array
let item_index = Object.values(dataTimeName).findIndex(v=>v===current);
let previousArray=Object.entries(dataTimeName).filter((_,index)=>index<item_index);

console.log(previousArray);

// general
console.log(
  Object.entries(dataTimeName)
  .filter(([key,value])=>parseInt(value.replace(':', '')) < parseInt(current.replace(':', '')))
)

// And if you need the result be a json object like first one:

console.log(
  Object.entries(dataTimeName)
  .reduce((r,[key,value])=>{
      if (parseInt(value.replace(':', '')) < parseInt(current.replace(':', ''))) r[key]=value;
      return r;
    }
  ,{})
)

// And if you need only the previous time:
let prev = Object.values(dataTimeName).filter((_,index)=>index<item_index)?.pop();
console.log(prev);

edited Jan 31, 2021 at 14:29

answered Jan 30, 2021 at 9:33

Vahid Alimohamadi

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2 Comments

HiDayurie Dave Over a year ago

Hi, just now tried your code. But I only need last previous result. So what expected is only get 12:17

Vahid Alimohamadi Over a year ago

You wrote: previousArray so i wrote this, i'll update

Clément Cartier · Accepted Answer · 2021-01-30 09:15:04Z

0

You could store the value of the previous iteration outside of the foreach function and update it at the end of the function.

But maybe if your object have to be ordered in a specific way it might be easier to store it as a classical array so you could access the previous value by dataTime[key-1]

Also be carefull because the previous value will not be defined for the first iteration.

answered Jan 30, 2021 at 9:15

Clément Cartier

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