arrays sort 2d array java

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

Arrays.sort(contests, (a, b) -> Integer.compare(b[0],a[0])); //decreasing order
    
Arrays.sort(contests, (a, b) -> Integer.compare(a[0],b[0]); //increasing order

Arrays.sort(myArr,(double[] a,double[] b)->{
                //here multiple lines of code can be placed
                return a[0]-b[0]; 
            });