How to initialize an array in Java
An array is a collection of data objects of the same type. It is one of the fundamental data structures in Java and is incredibly useful for solving programming problems.
The values stored in the array are referred to as elements and each element is present at a particular index of the array.
Declaring an array
The syntax for declaring an array is:
datatype[] arrayName;
-
datatype: The type of Objects that will be stored in the array eg.int,charetc. -
[ ]: Specifies that the declared variable points to an array
-
arrayName: Specifies the name of the array
Initializing an array
Declaring an array does not initialize it. In order to store values in the array, we must initialize it first, the syntax of which is as follows:
datatype [ ] arrayName = new datatype [size];
There are a few different ways to initialize an array. Look at the following examples to get a better idea about array initialization.
1. Initializing an array without assigning values:
An array can be initialized to a particular size. In this case, the default value of each element is 0.
class HelloWorld {public static void main( String args[] ) {//Initializing arrayint[] array = new int[5];//Printing the elements of arrayfor (int i =0;i < 5;i++){System.out.println(array[i]);}}}
2. Initializing an array after a declaration:
An array can also be initialized after declaration.
class HelloWorld {public static void main( String args[] ) {//Array Declarationint[] array;//Array Initializationarray = new int[]{1,2,3,4,5};//Printing the elements of arrayfor (int i =0;i < 5;i++){System.out.println(array[i]);}}}
Note: When assigning an array to a declared variable, the
newkeyword must be used.
3. Initializing an array and assigning values:
An array can also be initialized during declaration.
class HelloWorld {public static void main( String args[] ) {int[] array = {11,12,13,14,15};//Printing the elements of arrayfor (int i =0;i < 5;i++){System.out.println(array[i]);}}}
Note: When assigning values to an array during initialization, the size is not specified.
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