Showing posts with label Scala. Show all posts
Showing posts with label Scala. Show all posts

Saturday, July 26, 2014

Difference between sorted, sortWith and sortBy in Scala

Scala collections provide you three options for sorting: sorted( ), sortWith( ) and sortBy( ). Here is a simplified explanation:

sorted
Will sort the list using the natural ordering (based on the implicit Ordering passed)

sortBy (an attribute)
Sort by a given attribute using the attribute's type.
e.g. given a list of Person objects, if you want to sort them in ascending order of their age (which is an Int), you could simply say: personList.sortBy(_.age)

sortWith (a function)
Takes a comparator function. Useful when you want to specify a custom sorting logic. 
e.g. if you want to sort by age descending, you could write this as: 

personList.sortWith{(leftE,rightE) => 
     leftE.age > rightE.age
}

Or, more simply: personList.sortWith(_.age > _.age)

Checkout this gist for a full example: 
https://gist.github.com/gsluthra/80555ed4af24bea244b5