System.out.println("Minimum: " + Collections.min(ll));
System.out.println("Maximum: " + Collections.max(ll));
}
}
Output from this program is shown here:
List sorted in reverse: 20 8 -8 -20
List shuffled: 20 -20 8 -8
Minimum: -20
Maximum: 20
Notice that min( ) and max( ) operate on the list after it has been shuffled. Neither requires
a sorted list for its operation.
Arrays
The Arrays class provides various methods that are useful when working with arrays. These
methods help bridge the gap between collections and arrays. Each method defined by
Arrays is examined in this section.
The asList( ) method returns a List that is backed by a specified array. In other words,
both the list and the array refer to the same location. It has the following signature:
static <T> List asList(T ... array)
Here, array is the array that contains the data.
The binarySearch( ) method uses a binary search to find a specified value. This method
must be applied to sorted arrays. Here are some of its forms. (Java SE 6 adds several others.)
static int binarySearch(byte array[ ], byte value)
static int binarySearch(char array[ ], char value)
static int binarySearch(double array[ ], double value)
static int binarySearch(float array[ ], float value)
static int binarySearch(int array[ ], int value)
static int binarySearch(long array[ ], long value)
static int binarySearch(short array[ ], short value)
static int binarySearch(Object array[ ], Object value)
static <T> int binarySearch(T[ ] array, T value, Comparator<? super T> c)
Here, array is the array to be searched, and value is the value to be located. The last two forms
throw a ClassCastException if array contains elements that cannot be compared (for example,
Double and StringBuffer) or if value is not compatible with the types in array. In the last form,
the Comparator c is used to determine the order of the elements in array. In all cases, if value
exists in array, the index of the element is returned. Otherwise, a negative value is returned.
The copyOf( ) method was added by Java SE 6. It returns a copy of an array and has the
following forms:
static boolean[ ] copyOf(boolean[ ] source, int len)
static byte[ ] copyOf(byte[ ] source, int len)
static char[ ] copyOf(char[ ] source, int len)
static double[ ] copyOf(double[ ] source, int len)
static float[ ] copyOf(float[ ] source, int len)
Search WWH :
