Java byte Array

byte Array in Java

Java byte Array is used to store byte data type values only. The default value of the elements in a byte array is 0.

With the following Java byte array examples you can learn

  • how to declare Java byte array
  • how to assign values to Java byte array
  • how to get values from Java byte array

Initializing a byte Array in Java

Arrays are declared with [] (square brackets). If you put [] (square brackets) after any variable of any type only that variable is of type array remaining variables in that declaration are not array variables those are normal variables of that type.

If you put [] (square brackets) after any data type all the variables in that declaration are array variables. All the elements in the array are accessed with index. The array element index is starting from 0 to n-1 number i.e. if the array has 5 elements then starting index is 0 and ending index is 4.

// declares an array of bytes
byte[] byteArray;

What is the Length of an Array in Java ?

In Java all the arrays are indexed and declared by int only. That is the size of an array must be specified by an int value and not long or short. All the arrays index beginning from 0 to ends at 2147483646. You can store elements upto 2147483647. If you try to store long (big) elements in array, you will get performance problems. If you overcome performance problems you should go to java collection framework or simply use Vector.

Syntax :
                        < data type > < variable >[];
                        < data type >[] < variable >
			    

Java byte Array Example

/* Java byte Array Example */
/* Save with file name ByteArray.java */

public class ByteArray
{
	public static void main(String args[])
	{
		//JAVA BYTE ARRAY DECLARATION

		byte b[];

		//MEMORY ALLOCATION FOR JAVA BYTE ARRAY

		b = new byte[4];

		//ASSIGNING ELEMENTS TO JAVA BYTE ARRAY

		b[0] = 20;

		b[1] = 10;

		b[2] = 30;

		b[3] = 5;

		//BYTE ARRAY OUTPUT

		System.out.println("Java byte Array Example");

		for(int i=0;i<b.length;i++)
		{
			System.out.println("Element at Index : "+ i + " " + b[i]);
		}
	}
}
				    

Following Java byte array example you can learn how to assign values to java byte array at the time of declaration.

How to assign values to java byte array at the time of declaration

/* How to assign values to java byte array at the time of declaration Example */
/* Save with file name ByteArray2.java */

public class ByteArray2
{
	public static void main(String args[])
	{
		//JAVA BYTE ARRAY DECLARATION AND ASSIGNMENT

		byte b[] = {20,10,30,5};

		//JAVA BYTE ARRAY OUTPUT

		System.out.println("Java byte Array Example");

		for(int i=0;i<b.length;i++)
		{
			System.out.println("Element at Index : "+ i + " " + b[i]);
		}
	}
}
				    

Following Java byte array example you can learn how to declare Java byte array with other Java byte array variables.

How to declare Java byte array with other Java byte array variables

/* How to declare Java byte array with other Java byte array variables Example */
/* Save with file name ByteArray3.java */

public class ByteArray3
{
	public static void main(String args[])
	{
		//JAVA BYTE ARRAY DECLARATION

		byte b[], a; //b IS AN ARRAY a IS NOT AN ARRAY

		//MEMORY ALLOCATION FOR JAVA BYTE ARRAY

		b = new byte[4];

		//ASSIGNING ELEMENTS TO JAVA BYTE ARRAY

		b[0] = 20;

		b[1] = 10;

		b[2] = 30;

		b[3] = 5;

		a = 100;

		//JAVA BYTE ARRAY OUTPUT

		System.out.println("Java byte Array Example");

		System.out.println("a value is : "+a);

		for(int i=0;i<b.length;i++)
		{
			System.out.println("Element at Index : "+ i + " " + b[i]);
		}
	}
}
				    

Following Java byte array example you can learn how to assign Java byte array to other Java byte array.

How to assign Java byte array to other Java byte array

/* How to assign Java byte array to other Java byte array Example */
/* Save with file name ByteArray4.java */

public class ByteArray4
{
	public static void main(String args[])
	{
		//JAVA BYTE ARRAY DECLARATION

		byte[] a, b; //a AND b ARE ARRAY VARIABLES

		//MEMORY ALLOCATION FOR JAVA BYTE ARRAY

		b = new byte[4];

		//ASSIGNING ELEMENTS TO JAVA BYTE ARRAY

		b[0] = 20;

		b[1] = 10;

		b[2] = 30;

		b[3] = 5;

		//ASSIGNING b ARRAY TO a ARRAY VARIABLE

		a = b;

		//JAVA BYTE ARRAY OUTPUT

		System.out.println("Java byte Array Example");

		System.out.println("b array values");

		for(int i=0;i<b.length;i++)
		{
			System.out.println("Element at Index : "+ i + " " + b[i]);
		}
		System.out.println("a array values");

		for(int i=0;i<b.length;i++)
		{
			System.out.println("Element at Index : "+ i + " " + a[i]);
		}
	}
}