How to filter an array based on Month comparison and get Max Date() in Angular?-CodePudding

I have an array of objects with a date value. I want to filter the array based on the selectedDate and get the Max date in the list of dates. In the below code, I am filtering the array based on the month. Here I get 3 values after filtering, now I want to compare those values and get the MAX Date() value.

How can I do that in Angular or ES6 way?

let selectedDate = new Date();
let array = [{
    "date": "2022-08-30T23:00:00Z",
    "value": "4.0"
  },
  {
    "date": "2022-08-28T23:00:00Z",
    "value": "8.0"
  },
  {
    "date": "2022-08-25T23:00:00Z",
    "value": "2.0"
  },
  {
    "date": "2022-07-25T23:00:00Z",
    "value": "2.0"
  }
];

let x = array.filter(d =>
  new Date(d.date).getMonth() === selectedDate.getMonth() - 1
)
console.log(x)

Expected Output:
{
  "date": "2022-08-30T23:00:00Z",
  "value": "4.0"
}

CodePudding user response：

let yourOutput = [
  {
    "date": "2022-08-30T23:00:00Z",
    "value": "4.0"
  },
  {
    "date": "2022-08-28T23:00:00Z",
    "value": "8.0"
  },
  {
    "date": "2022-08-25T23:00:00Z",
    "value": "2.0"
  }
];
//Sort by Date
yourOutput.sort((a, b) => new Date(a) > new Date(b));
//Get First Elem
if(yourOutput.length > 0) {
    console.log(yourOutput[0])
}

CodePudding user response：

I think you can use reduce function afterfilter to get the max.

Assuming we have 2 variables, selectedDate and array:

let max = array
    .filter(d =>
      new Date(d.date).getMonth() === selectedDate.getMonth() - 1
    )
    .reduce((max, current) => {
        if (!max) return current;
        let maxDate = new Date(max.date);
        let currentDate = new Date(current.date);
        return maxDate > currentDate? max: current;
    }, null);