Methods provided by the Collections class

The Collections class in Java provides several useful methods for working with collections. These methods make it easier to perform common tasks such as searching, sorting, and manipulating collections. This article will introduce some of the most commonly used methods provided by the Collections class.

1. Sorting Methods

sort(List<T> list)

This method is used to sort the elements of the specified list in ascending order. The elements in the list must implement the Comparable interface or a custom Comparator should be provided.

reverse(List<T> list)

This method is used to reverse the order of the elements in the specified list.

shuffle(List<T> list)

This method is used to randomly permute the elements in the specified list.

2. Searching Methods

binarySearch(List<? extends Comparable<? super T>> list, T key)

This method is used to perform a binary search on the specified list for the specified key. The list must be sorted in ascending order according to the natural ordering of its elements.

binarySearch(List<? extends T> list, T key, Comparator<? super T> c)

This method is used to perform a binary search on the specified list for the specified key using a custom comparator.

3. Synchronization Methods

synchronizedCollection(Collection<T> c)

This method returns a synchronized (thread-safe) collection backed by the specified collection.

synchronizedList(List<T> list)

This method returns a synchronized (thread-safe) list backed by the specified list.

synchronizedSet(Set<T> s)

This method returns a synchronized (thread-safe) set backed by the specified set.

4. Other Useful Methods

max(Collection<? extends T> coll)

This method returns the maximum element of the given collection according to the natural ordering of its elements.

min(Collection<? extends T> coll)

This method returns the minimum element of the given collection according to the natural ordering of its elements.

frequency(Collection<?> c, Object o)

This method returns the number of occurrences of the specified element in the specified collection.

addAll(Collection<? super T> c, T... elements)

This method adds all of the specified elements to the specified collection.

These are just a few of the methods provided by the Collections class in Java. There are many more methods available that can help you manipulate and work with collections efficiently.