{"id":11774,"date":"2023-01-17T10:02:28","date_gmt":"2023-01-17T10:02:28","guid":{"rendered":"https:\/\/www.prepbytes.com\/blog\/?p=11774"},"modified":"2023-04-24T11:48:44","modified_gmt":"2023-04-24T11:48:44","slug":"array-vs-arraylist","status":"publish","type":"post","link":"https:\/\/prepbytes.com\/blog\/array-vs-arraylist\/","title":{"rendered":"Difference between Array and ArrayList"},"content":{"rendered":"

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In this article we\u2019ll see the Array vs ArrayList. The data structures Array<\/a><\/strong> vs ArrayList<\/strong> are well-known in Java. While ArrayList is a class of the Java Collections framework, an array is a fundamental Java feature. It is a part of the java.util package. <\/p>\n

Java Array<\/h2>\n

An object that is formed dynamically is an array. It functions as a holding area for a certain number of values of the same kind. It has an uninterrupted memory space. We are unable to alter an array’s size once it has been established. The next sentence may be used to create an array:<\/p>\n

int array[]=new int[size];<\/code><\/pre>\n
An array of the requested size is created by the previous command. It produces an ArrayIndexOutOfBoundsException when we attempt to add more than its size. For instance<\/p>\n
int arr[]=new int[3];   \/\/specified size of the array is 3  \n\/\/adding 4 elements into array   \narr[0]=12;  \narr[1]=2;  \narr[2]=15;  \narr[3]=67;  <\/code><\/pre>\n
Java ArrayList Class<\/h2>\n
In Java, ArrayList<\/strong> is a class of Collections framework. It implements List, Collection, Iterable, Cloneable, Serializable,<\/strong> and RandomAccess<\/strong> interfaces. It extends AbstractList<\/strong> class.<\/p>\n
We can create an instance of ArrayList by using the following statement:<\/p>\n
ArrayList arrayList=new ArrayList();  <\/code><\/pre>\n
In Java, the array serves as the internal backing for ArrayList. The ArrayList’s resize action slows down speed since it creates a new array and copies data from an old array to the new array. It uses System.arraycopy(sec, srcPos, dest, destPos, length)<\/strong> which is a natively implemented function.
\nPrimitive types cannot be stored in an array list. Thus, it only stores objects. Primitive types are automatically converted to objects. For instance, we created an object called an ArrayList.<\/p>\n
ArrayList  list=new ArrayList();  \/\/object of ArrayList  \narrayObj.add(12);   \/\/trying to add integer primitive to the ArrayList  <\/code><\/pre>\n
Through automatic boxing, the JVM transforms it into an integer object.<\/p>\n
ArrayList arrayObj=new ArrayList()\/\/object of ArrayList  \narrayObj(new Integer(12)); \/ArrayList object is inserted when the raw integer is converted to an integer object.<\/code><\/pre>\n
Similarities Between an Array and Arraylist<\/h2>\n
    \n
  • Array vs ArrayList is used to store elements.<\/li>\n
  • Both Array vs ArrayList can contain null values.<\/li>\n
  • They may contain identical values.<\/li>\n
  • The arrangement of the components is not maintained.<\/li>\n<\/ul>\n
    Difference Between Array and ArrayList<\/h2>\n
    The fundamental distinctions between Array vs ArrayList are shown in the following table:<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
    Basis<\/th>\nArray<\/th>\nArrayList<\/th>\n<\/tr>\n<\/thead>\n
    Definition<\/td>\nAn object that is formed dynamically is an array. It functions as a holding area for a certain number of values of the same kind. It has an uninterrupted memory space.<\/td>\nA class in the Java Collections framework is the ArrayList. It includes well-known classes like HashTable, Vector, and HashMap.<\/td>\n<\/tr>\n
    The static\/ Dynamic<\/td>\nSize of an array is fixed.<\/td>\nThe size of an ArrayList list is dynamic.<\/td>\n<\/tr>\n
    Resizable<\/td>\nA fixed-length data structure is an array.<\/td>\nA data structure with a changeable length is an ArrayList. If necessary, it can resize itself.<\/td>\n<\/tr>\n
    Initialization<\/td>\nWhen directly or indirectly initializing an array, the size must be provided.<\/td>\nAn ArrayList object can be created without a size being specified. A default-sized ArrayList is created by Java.<\/td>\n<\/tr>\n
    Performance<\/td>\nDue to its constant size, it performs quickly compared to ArrayList.<\/td>\nIn Java, the array serves as the internal support for ArrayList. Performance is slowed down by the ArrayList’s resize process.<\/td>\n<\/tr>\n
    Primitive\/ Generic type<\/td>\nBoth primitives and objects can be stored in an array.<\/td>\nPrimitive types cannot be stored in an ArrayList. Primitive types are automatically converted to objects.<\/td>\n<\/tr>\n
    Iterating Values<\/td>\nTo iterate through an array, we use a for loop or a for each loop.<\/td>\nTo iterate through an ArrayList, we need an iterator.<\/td>\n<\/tr>\n
    Type-Safety<\/td>\nBecause it is not a convertible type of array, we cannot utilize generics with the array.<\/td>\nit Because ArrayList only lets us store generic\/type data, it is type-safe.<\/td>\n<\/tr>\n
    Length<\/td>\nThe length of an array is indicated by a length variable that is provided by the array.<\/td>\nTo calculate the size of an ArrayList, use the size() function provided by ArrayList.<\/td>\n<\/tr>\n
    Adding Elements<\/td>\nThe assignment operator can be used to add elements to an array.<\/td>\nThe add() function in Java allows you to add elements to an ArrayList.<\/td>\n<\/tr>\n
    Single\/ Multi-Dimensional<\/td>\nArray can be multi-dimensional.<\/td>\nArrayList is always single-dimensional.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    Array example in Java:<\/h3>\n
    In the example below, we have just constructed an array with a length of four.<\/p>\n\t\t\t\t\t\t