Java Arrays 

Introduction

In Java, an array is a data structure that allows you to store multiple values of the same type. It provides a convenient way to organize and manipulate collections of data.

Declaration and Initialization

To declare an array in Java, you specify the type of the elements followed by the array name:

type[] arrayName;

For example, to declare an integer array:

int[] numbers;

Arrays can be initialized in two ways:

• Using the new keyword:

arrayName = new type[arraySize];

• Inline initialization:

type[] arrayName = {value1, value2, ..., valueN};

Accessing and Modifying Elements

Array elements are accessed using their index, which starts at 0. You can use the index in square brackets [] to access or modify an element:

// Accessing elements
type element = arrayName[index];

// Modifying elements
arrayName[index] = newValue;

Array Length

You can obtain the length of an array using the length property:

int size = arrayName.length;

Iterating over an Array

Looping constructs like for or foreach can be used to iterate over the elements of an array:

// Using a for loop
for (int i = 0; i < arrayName.length; i++) {
  // Process array element
}

// Using a foreach loop
for (type element : arrayName) {
  // Process array element
}

One Dimensional(1 D)

 //java array program and ouput index wise
		int [] x={400,300,200,500};
		System.out.println(x[0]);
		System.out.println(x[1]);
		System.out.println(x[2]);
		System.out.println(x[3]);

		// Java array prg and Output before change/After change
		
      String y[]={"a","b","c","d"};
      for(int i=0;i<y.length;i++)
      {
    	  System.out.println(y[i]);
      }
	  //-----After Change
		y[1]="Code2night";
		
		for(String xyz:y)
		{
			System.out.println(xyz);
		}
		
		// As an object
		
		int abc [] = new int[4];
		abc[0]=101;
		abc[1]=201;
		abc[2]=301;
		abc[3]=401;
		for(int xyz :abc)
		{
			System.out.println(xyz);
		}

Conclusion

Java arrays are a fundamental part of the language, allowing you to store and manipulate collections of data. Understanding how to declare, initialize, and work with arrays is crucial for Java developers.