Arranging elements by date in JavaScript

Question

Arranging elements by date in JavaScript

element, I am currently utilizing the sort() method to arrange an Array based on date values. The issue arises when some elements within the data array are missing valid dates or have incorrect formats, leading to an error message stating: "Cannot read property 'getTime' of undefined." An update to my situation is that I now have moment.js available for use. With this in mind, where would be the appropriate place to validate whether a date is valid before using it to sort the array? Provided below is the sample data I am working with:

[{
        "date": "2019-06-15 14:57:13",
        "user": "john"
    },
    {
        "date": "2019-06-15 05:48:01",
        "user": "mike"
    },
    {
        "date": "bad-date-format",
        "user": "donna"
    },
    {
        "date": "2019-06-08 10:45:09",
        "user": "Ismil"
    },
    {
        "date": "",
        "user": "Daniel17"
    }
]

In contrast, here is the desired output after sorting:

[
    {
        "date": "2019-06-15 14:57:13",
        "user": "john"
    },
    {
        "date": "2019-06-15 05:48:01",
        "user": "mike"
    },
    {
        "date": "2019-06-08 10:45:09",
        "user": "Ismil"
    },
    {
        "date": "bad-date-format",
        "user": "donna"
    },
    {
        "date": "",
        "user": "Daniel17"
    }
]

javascript arrays

Answer 1

Answer №1

There is no need to verify if the string represents a valid date.

Check out this functional code snippet:

const data = [{
        "date": "2019-06-15 14:57:13",
        "user": "john"
    },
    {
        "date": "2019-06-15 05:48:01",
        "user": "mike"
    },
    {
        "date": "bad-date-format",
        "user": "donna"
    },
    {
        "date": "2019-06-08 10:45:09",
        "user": "Ismil"
    },
    {
        "date": "",
        "user": "Daniel17"
    }
];

const elements = data.sort((a, b) => (new Date(b.date).getTime() || -Infinity) - (new Date(a.date).getTime() || -Infinity));
console.log(elements);

The logic behind the code above lies in using new Date(), which returns an Invalid Date object for invalid date strings and then NaN when calling its getTime() method.

By sorting with the condition that Invalid Dates should be at the end, the -Infinite value ensures they are placed last in the array as it represents the lowest possible number.

In this scenario, the order of Invalid Date entries at the end of the array should not impact the overall functionality.

Answer 2

There is no need to verify if the string represents a valid date.

Check out this functional code snippet:

const data = [{
        "date": "2019-06-15 14:57:13",
        "user": "john"
    },
    {
        "date": "2019-06-15 05:48:01",
        "user": "mike"
    },
    {
        "date": "bad-date-format",
        "user": "donna"
    },
    {
        "date": "2019-06-08 10:45:09",
        "user": "Ismil"
    },
    {
        "date": "",
        "user": "Daniel17"
    }
];

const elements = data.sort((a, b) => (new Date(b.date).getTime() || -Infinity) - (new Date(a.date).getTime() || -Infinity));
console.log(elements);

The logic behind the code above lies in using new Date(), which returns an Invalid Date object for invalid date strings and then NaN when calling its getTime() method.

By sorting with the condition that Invalid Dates should be at the end, the -Infinite value ensures they are placed last in the array as it represents the lowest possible number.

In this scenario, the order of Invalid Date entries at the end of the array should not impact the overall functionality.

Answer 3

Answer №2

To determine the correct sorting order for dates, you can first check if the property exists and has the desired format. Then, arrange the dates in descending order as strings. In cases where a date does not have a valid format, compare the boolean values instead.

function validateDate(dateString) {
    return typeof dateString === 'string'
        && /\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}/.test(dateString);
}

var arr = [{ date: "2019-06-15 14:57:13", user: "john" }, { date: "2019-06-15 05:48:01", user: "mike" }, { date: "bad-date-format", user: "donna" }, { date: "2019-06-08 10:45:09", user: "Ismil" }, { date: "", user: "Daniel17" }];

arr.sort((x, y) => {
    var xValid = validateDate(x.date),
        yValid = validateDate(y.date);

    return xValid && yValid
        ? y.date.localeCompare(x.date)
        : yValid - xValid;
});

console.log(arr);

.as-console-wrapper { max-height: 100% !important; top: 0; }

Answer 4

To determine the correct sorting order for dates, you can first check if the property exists and has the desired format. Then, arrange the dates in descending order as strings. In cases where a date does not have a valid format, compare the boolean values instead.

function validateDate(dateString) {
    return typeof dateString === 'string'
        && /\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}/.test(dateString);
}

var arr = [{ date: "2019-06-15 14:57:13", user: "john" }, { date: "2019-06-15 05:48:01", user: "mike" }, { date: "bad-date-format", user: "donna" }, { date: "2019-06-08 10:45:09", user: "Ismil" }, { date: "", user: "Daniel17" }];

arr.sort((x, y) => {
    var xValid = validateDate(x.date),
        yValid = validateDate(y.date);

    return xValid && yValid
        ? y.date.localeCompare(x.date)
        : yValid - xValid;
});

console.log(arr);

.as-console-wrapper { max-height: 100% !important; top: 0; }

Answer 5

Answer №3

Ensure your dates are valid by using the Date.parse method before sorting both parameters to compare them correctly. If one date is not valid, prioritize the other date as "higher":

let data = [{ "date": "2019-06-15 14:57:13", "user": "john" }, { "date": "2019-06-15 05:48:01", "user": "mike" }, { "date": "bad-date-format", "user": "donna" }, { "date": "2019-06-08 10:45:09", "user": "Ismil" }, { "date": "", "user": "Daniel17" } ]

let result = data.sort((a,b) => Date.parse(a.date) && Date.parse(b.date)
  ? new Date(b.date).getTime() - new Date(a.date).getTime()
  : Date.parse(a.date) ? -1 : 0
)

console.log(result)

Answer 6

Ensure your dates are valid by using the Date.parse method before sorting both parameters to compare them correctly. If one date is not valid, prioritize the other date as "higher":

let data = [{ "date": "2019-06-15 14:57:13", "user": "john" }, { "date": "2019-06-15 05:48:01", "user": "mike" }, { "date": "bad-date-format", "user": "donna" }, { "date": "2019-06-08 10:45:09", "user": "Ismil" }, { "date": "", "user": "Daniel17" } ]

let result = data.sort((a,b) => Date.parse(a.date) && Date.parse(b.date)
  ? new Date(b.date).getTime() - new Date(a.date).getTime()
  : Date.parse(a.date) ? -1 : 0
)

console.log(result)

Answer 7

Answer №4

According to the original poster's comment

Sort by descending date and place those without corrupt data at the beginning of the array

let data = [{
  date: new Date('2019-01-03T00:00:00.000Z')
},{
  date: new Date('2020-01-03T00:00:00.000Z')
},{
  date: new Date('2018-01-03T00:00:00.000Z')
}, {}]


function safeGetTime(obj) {
  if (obj && obj.date && obj.date.getTime) {
    return obj.date.getTime();
  }
  return Number.MAX_SAFE_INTEGER; // replace with `return 0` to put invalid data at end of array
}

data.sort(function(a, b) {
  return safeGetTime(b) - safeGetTime(a)
});

console.log(data);

Answer 8

According to the original poster's comment

Sort by descending date and place those without corrupt data at the beginning of the array

let data = [{
  date: new Date('2019-01-03T00:00:00.000Z')
},{
  date: new Date('2020-01-03T00:00:00.000Z')
},{
  date: new Date('2018-01-03T00:00:00.000Z')
}, {}]


function safeGetTime(obj) {
  if (obj && obj.date && obj.date.getTime) {
    return obj.date.getTime();
  }
  return Number.MAX_SAFE_INTEGER; // replace with `return 0` to put invalid data at end of array
}

data.sort(function(a, b) {
  return safeGetTime(b) - safeGetTime(a)
});

console.log(data);

Answer 9

Answer №5

data.filter(function(item) {
    if (typeof item.price !== 'undefined' && typeof item.quantity !== 'undefined') {
        return item.price * item.quantity
    }
    return 0;
});

Example of filtering data

data = [{price: 100, quantity: 2},{price:null, quantity:3},{price:50, quantity: 5}, {noPrice:10}];

data.filter(function(item) {
    if (typeof item.price !== 'undefined' && typeof item.quantity !== 'undefined') {
      return item.price + item.quantity
    }
    return 0
});

console.log(data)

Answer 10

data.filter(function(item) {
    if (typeof item.price !== 'undefined' && typeof item.quantity !== 'undefined') {
        return item.price * item.quantity
    }
    return 0;
});

Example of filtering data

data = [{price: 100, quantity: 2},{price:null, quantity:3},{price:50, quantity: 5}, {noPrice:10}];

data.filter(function(item) {
    if (typeof item.price !== 'undefined' && typeof item.quantity !== 'undefined') {
      return item.price + item.quantity
    }
    return 0
});

console.log(data)

Answer 11

Answer №6

To implement this logic, utilize the && operator.

data.sort(function(a, b) {
    return (a.date && b.date && a.date.getTime && b.date.getTime && a.date.getTime() - b.date.getTime()) || 0
});

If you prefer a cleaner approach, consider using a helper function.

const validDate = (...arr) => arr.every(x => x.date && x.date.getTime);
data.sort(function(a, b) {
    return (validDate(a,b) && a.date.getTime() - b.date.getTime()) || 0
});

Answer 12

To implement this logic, utilize the && operator.

data.sort(function(a, b) {
    return (a.date && b.date && a.date.getTime && b.date.getTime && a.date.getTime() - b.date.getTime()) || 0
});

If you prefer a cleaner approach, consider using a helper function.

const validDate = (...arr) => arr.every(x => x.date && x.date.getTime);
data.sort(function(a, b) {
    return (validDate(a,b) && a.date.getTime() - b.date.getTime()) || 0
});

Answer 13

Answer №7

Always validate with getTime before proceeding further.

let records = [{
  date: new Date('2019-01-03T00:00:00.000Z')
},{
  date: new Date('2020-01-03T00:00:00.000Z')
},{
  date: new Date('2018-01-03T00:00:00.000Z')
}, {}]

records.sort((a, b)=>{
  if(!isNaN(new Date(a.date).getTime()) && !isNaN(new Date(b.date).getTime())){
  return a.date.getTime() - b.date.getTime()
  } 
  return Infinity
});

console.log(records);

Answer 14

Always validate with getTime before proceeding further.

let records = [{
  date: new Date('2019-01-03T00:00:00.000Z')
},{
  date: new Date('2020-01-03T00:00:00.000Z')
},{
  date: new Date('2018-01-03T00:00:00.000Z')
}, {}]

records.sort((a, b)=>{
  if(!isNaN(new Date(a.date).getTime()) && !isNaN(new Date(b.date).getTime())){
  return a.date.getTime() - b.date.getTime()
  } 
  return Infinity
});

console.log(records);

Arranging elements by date in JavaScript

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

Answer №6

Answer №7

Similar questions

Is Highcharts-angular (Highcharts wrapper for Angular) compatible with Angular 4?

Is there a way to access the userID in the React.js front-end?

What is the best way to validate a particular class in javascript?

Is it possible to modify the stroke color of the progress circle in ng-zorro?

When $refs is not defined, it means that it is still functional and operational

The video is not displaying on the webpage when connected locally, but it appears when the source is a URL

Exploring the effectiveness of testing Svelte components

difference of arrays

Sending HTML content to viewChild in Angular 5

Arranging elements within an array using the C programming language

Incorporate Thymeleaf's HTML using the powerful JavaScript framework, jQuery

Creating an array with string keys and values using two foreach loops in PHP

Choosing choices from an array of values in a selection box

Design a 3D visualization of a stack using data points in the Three.js platform

Show a message on form submission rather than redirecting

Open Chrome in fullscreen mode directly from your Android home screen without the statusbar displayed

Introduce a pause for each individual element when looping through an array

Executing a Ruby on Rails controller method from JavaScript

Unlocking the mysteries of JavaScript: Understanding the significance of the tilde symbol preceding the ternary IF operator

Can I simultaneously execute nodemon and browser-sync using a single npm script for an Express application?