int[] t = { 56, 12, 9, 2, 4, 6, 1, 0, 297, 100, -56 };
//---			
int pos = Arrays.binarySearch( t, 4 );
System.out.println( "pos= " + pos );
//---	
Arrays.sort( t );
System.out.println( "tableau trié: " + Arrays.toString( t ) );
//---
pos = Arrays.binarySearch( t, 4 );
System.out.println( "pos= " + pos );