How to Sort an Array of Objects by Property in JavaScript

If compareFn is not supplied, all non-undefined array elements are sorted by converting them to strings and comparing strings in UTF-16 code units order. In a numeric sort, 9 comes before 80, but because numbers are converted to strings, “80” comes before “9” in the Unicode order. All undefined elements are sorted to the end of the array.

• In this article, we’ll show you how to sort an array of objects in JavaScript using strings, numbers, and dates.
• If the source array is sparse, the empty slots are moved to the end of the array, and always come after all the undefined.
• For descending order, we can replace the sort() function with reverse().
• This article will discuss how to sort an array of objects based on the values of the object’s properties.
• The sort method can be modified to sort anything like an array of numbers, strings and even objects using a compare function.
• If you want to sort the array without mutating it, use the spread syntax (…) to create a shallow copy before calling the sort() method.
• By the way, please do not encourage people to change the Array Prototype .

The more work a compareFn does and the more elements there are to sort, it may be more efficient to use map() for sorting. When you have an array of objects, it is more involved to do things like sorting and filtering because you have to dive into each object to get the value you want. The output is the same in both cases and can be used before sorting any array of objects. The compareFunction returns a number which is used to determine the sorting order by comparing its two inputs . Quite simply, if the integer is less than 0, a will appear before b. If it’s greater than 0, b will appear before a.

JavaScript Objects

@BadFeelingAboutThis what does returning either -1 or 1 mean? I understand that -1 literally means that A is less than B just by the syntax, but why use a 1 or -1? I see everyone is using those numbers as return values, but why? The property names are changed to uppercase using the toUpperCase() method.

However you determine that number is up to you. To compare the age property of two objects, we can simply subtract them. This results in “sorting by fn1”, “sorting by fn2” which is pretty much equal to ORDER BY in SQL.

sort() returns the reference to the same array

To sort an array of objects, you use the sort() method and provide a comparison function that determines the order of objects. Simply take advantage of the built-in sort method on arrays and you can sort an array of objects by any property by just comparing them. In this article, we’ll show you how to sort an array of objects in JavaScript using strings, numbers, and dates.

This method is like _.sortBy except that it allows specifying the sort orders of the iteratees to sort by. If orders is unspecified, all values are sorted in ascending order. Otherwise, specify an order of “desc” for descending or “asc” for ascending sort order of corresponding values. The a.value – b.value used to compare the object’s attributes can be adopted for the various times of data. For example, regex can be used to compare each pair of the neighboring strings.

Quick Tip: Sort an Array Of Objects by Date

The time and space complexity of the sort cannot be guaranteed as it depends on the implementation. The JavaScript Tutorial website helps you learn JavaScript programming from scratch quickly and effectively. Earn 10 reputation in order to answer this question.

The sort() function is used to sort the elements of an array alphabetically and not numerically. To get the items in reverse order, we may use the reverse() method. This will sort the employees array by the name property ascending, so employee is “Christine”, employee is “Edward” and so on. And as you might have just discovered, in JavaScript you can certainly compare two string . In our earlier example, we wanted to sort an array of objects, whose values are either strings or numbers. If, however, you know that you’ll only be dealing with objects whose values are strings, you can tidy up the code a little using JavaScript’s localeCompare method.

The compare function is only a single line, so it is provided directly with the sort() method. To get everything in descending order, use the reverse() function. We used theArray.sortmethod to sort an array of objects by a boolean property. In the code above, the hasOwnProperty method is used to check if the specified property is defined on each object and has not been inherited via the prototype chain. If it’s not defined on both objects, the function returns 0, which causes the sort order to remain as is (i.e. the objects remain unchanged with respect to each other). UsingArray.sort alone wouldn’t be very useful for sorting an array of objects.

This method compares the properties of the items in an array. In this short article – we took a look at sorting an array of objects based on a string property, using the sort() method in JavaScript. With the above sort method, the employees array is now sorted by the age property, so employee is “Edward”, employee is “George” etc. The typeof operator is also used to check the data type of the property’s value. This allows the function to determine the proper way to sort the array. In this example, you will learn to write a JavaScript program that will sort an array of objects by property values. In JavaScript, we use the sort() function to sort an array of objects.