java Arrays.sort 2d array

Question

I am looking to sort the following array based on the values of [][0]

double[][] myArr = new double[mySize][2]; 

so for example, myArr contents is:

1      5 13     1.55 12     100.6 12.1   .85 

I want it to get to:

1      5 12     100.6 12.1   .85 13     1.55 

I am looking to do this without having to implement my own sort.

Answer 1

Use Overloaded Arrays#Sort(T[] a, Comparator c) which takes Comparator as the second argument.

double[][] array= { {1, 5}, {13, 1.55}, {12, 100.6}, {12.1, .85} };  java.util.Arrays.sort(array, new java.util.Comparator<double[]>() {     public int compare(double[] a, double[] b) {         return Double.compare(a[0], b[0]);     } }); 

JAVA-8: Instead of that big comparator, we can use lambda function as following-

Arrays.sort(array, Comparator.comparingDouble(o -> o[0])); 

Answer 2

Welcome Java 8:

Arrays.sort(myArr, (a, b) -> Double.compare(a[0], b[0]));