Java Coding Problems

15. Sorting an array of strings by length

The first thing that comes to mind when sorting is the use of a comparator.

In this case, the solution should compare lengths of strings, and so the integers are returned by calling String.length() for each string in the given array. So, if the integers are sorted (ascending or descending), then the strings will be sorted.

The Java Arrays class already provides a sort() method that takes the array to sort and a comparator. In this case, Comparator<String> should do the job.

Before Java 7, code that implemented a comparator relied on the compareTo() method. Common usage of this method was to compute a difference of the x1-x2 type, but this computation may lead to overflows. This makes compareTo()