In this article, we will discuss Arrays class – a utility class for Collection framework for inter-conversion between arrays and List, which has useful methods for

• Sorting
• Searching
• Conversion to List
• etc

1. Arrays:

• All utility methods inside Arrays class are static
• Methods can be invoked directly using class-name, without creating instance
• This is mostly used for List; for inter-conversion between Arrays and List

2. Arrays method:

Arrays method	Description
void sort(primitive[] pmt);	here, primitive can be int, short, long, double, char, byte, float Note: only natural ordering is possible for primitive types
void sort(Object[] object);	any object implementing Comparable interface
void sort(Object[] o, Comparator c);	to sort any object based on specified Comparator
void binarySearch(primitive[] pmt, primitive e);	here, primitive can be int, short, long, double, char, byte, float   e –> element to be searched
void binarySearch(Object[] oArray, object obj);	obj is the object searched from specified object array
void binarySearch(Object[]oArray, object obj Comparator c);	obj is the object searched from specified object array based on specified Comparator
List asList(Object[] oArray);	Used to convert array into list object but actually a List reference not separate object

3. Advantages of Arrays :

• It is used to store one or more element/objects of same-type
• It can referred/accessed using single variable-name
• Easily any element can be accessed using index-position
• It can also be used to implement 2D matrices

4. Disadvantages of Arrays :

• Arrays size/length is fixed, which we need assign while creating/initializing
• Due to its fixed, it doesn’t increases when more elements need to be added or doesn’t get shrinks when elements are removed
• So, we all must know in advance about Arrays size, while creating/initializing itself
• Since Arrays stores elements in contagious location therefore it is time-consuming activity to insert/add or remove/delete elements
• If we under-utilised is more than its capacity, then memory gets wasted
• Similarly, it isn’t flexible to add/insert more elements

Related Articles:

• Arrays class
• Arrays v/s ArrayList
• Java – Various ways to iterate Arrays in 5 ways
• Java – How to find duplicate in String Arrays ?
• Java – Various ways to remove duplicate elements from Arrays – 5 ways
• Java – Searching element from Arrays using Binary Search Algorithm

References:

• https://docs.oracle.com/javase/tutorial/collections/intro/
• https://docs.oracle.com/javase/tutorial/collections/interfaces/collection.html
• https://docs.oracle.com/javase/7/docs/api/java/util/Collection.html
• https://docs.oracle.com/javase/7/docs/api/java/util/Arrays.html
• https://docs.oracle.com/javase/tutorial/java/nutsandbolts/arrays.html
• https://docs.oracle.com/javase/7/docs/api/java/lang/reflect/Array.html
• https://docs.oracle.com/javase/specs/jls/se7/html/jls-10.html

Happy Coding !!
Happy Learning !!