How to sort String array by length using Arrays.sort()

Question

I am trying to sort an array of strings according to their length using Arrays.sort(), but this sorts the strings lexicographically rather than by length. Here is my code:

S = "No one could disentangle correctly"
String W[] = S.split(" ");
Arrays.sort(W);

After sorting :

correctly
could
disentangle
no
one

but what I want is

no  //length = 2
one //length = 3
could //length = 4 and likewise
correctly
disentangle

How can I get the above output? Please give answer for JDK 1.7 & JDK1.8.

Answer 1

For java 8 and above

 Arrays.sort(W, (a, b)->Integer.compare(a.length(), b.length()));

A more concise way is to use Comparator.comparingInt from Mano's answer here.

Answer 2

Alternative to and slightly simpler than matt's version

Arrays.sort(W, Comparator.comparingInt(String::length));

Answer 3

If you are using JDK 1.8 or above then you could use lambda expression like matt answer. But if you are using JDK 1.7 or earlier version try to write a custom Comparator like this:

String S = "No one could disentangle correctly";
String W[] = S.split(" ");
Arrays.sort(W, new java.util.Comparator<String>() {
    @Override
    public int compare(String s1, String s2) {
        // TODO: Argument validation (nullity, length)
        return s1.length() - s2.length();// comparision
    }
});