Sorting an ArrayList of custom objects by a particular property is a common task in software development.
In Kotlin, this can be achieved easily using the built-in sorting functions provided by the language.
In this tutorial, we will discuss how to sort an ArrayList of custom objects by property in Kotlin.
Assuming we have a custom object named Person with properties name, age, and address.
We have an ArrayList of Person objects named peopleList. Our goal is to sort this ArrayList by the age property of each Person object.
To sort an ArrayList in Kotlin, we can use the sortedBy function.
The sortedBy function takes a lambda function that returns the property by which we want to sort the ArrayList.
In our case, we want to sort the ArrayList by the age property of each Person object.
So, we will write the lambda function as follows:
val sortedList = peopleList.sortedBy { it.age }The it keyword in the lambda function refers to each Person object in the ArrayList.
The sortedBy function returns a new ArrayList that is sorted based on the property specified in the lambda function.
In this case, the sortedList ArrayList will be sorted by the age property of each Person object.
If we want to sort the ArrayList in descending order, we can use the sortedByDescending function instead.
The usage is similar to the sortedBy function, except that it sorts the ArrayList in descending order.
val sortedListDescending = peopleList.sortedByDescending { it.age }The sortedListDescending ArrayList will be sorted by the age property of each Person object in descending order.
In conclusion, sorting an ArrayList of custom objects by property in Kotlin is a straightforward task that can be accomplished using the sortedBy and sortedByDescending functions provided by the language.
By passing a lambda function that returns the property by which we want to sort the ArrayList, we can easily sort the ArrayList in ascending or descending order.
