Array Working and Types

Lecture 46:-  Array Working and Types

Arrays in Java are data structures that allow you to store a fixed-size collection of elements of the same data type. They provide a way to group related values under a single variable name. Arrays are widely used in programming to efficiently store and access multiple elements of data.

Working of Arrays in Java:

1. Declaration and Initialization: To create an array, you need to declare the array variable and initialize it with the desired number of elements. The elements of the array are accessed using an index, which starts from 0 and goes up to the size of the array minus one.

   javaCopy code
   // Declaration and initialization of an array of integers
   int[] numbers = new int[5];
   numbers[0] = 10;
   numbers[1] = 20;
   numbers[2] = 30;
   numbers[3] = 40;
   numbers[4] = 50;
   

2. Accessing Elements: You can access individual elements of an array using their index within square brackets. For example, to access the second element of the numbers array:

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   int secondElement = numbers[1]; // secondElement = 20
   

3. Length of the Array: You can obtain the length of the array using the length property. The length is the number of elements the array can hold.

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   int arrayLength = numbers.length; // arrayLength = 5
   

Types of Arrays in Java:

1. Single-Dimensional Arrays: These are the most common type of arrays in Java. They have a single row and can be thought of as a list of elements. Elements are accessed using a single index.

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   int[] numbers = new int[5];
   

2. Multi-Dimensional Arrays: Multi-dimensional arrays are arrays of arrays. They can have multiple rows and columns. Elements are accessed using two or more indices.

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   int[][] matrix = new int[3][3];
   

3. Jagged Arrays: Jagged arrays are multi-dimensional arrays where each row can have a different number of elements. They are arrays of arrays, but each inner array can have a different length.

   javaCopy code
   int[][] jaggedArray = new int[3][];
   jaggedArray[0] = new int[3];
   jaggedArray[1] = new int[2];
   jaggedArray[2] = new int[4];
   

4. Arrays of Objects: In Java, arrays can also hold objects, such as strings or custom classes.

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   String[] names = new String[3];
   names[0] = "Alice";
   names[1] = "Bob";
   names[2] = "Charlie";
   

Arrays are powerful data structures that are fundamental to Java and many other programming languages. They are widely used for storing and processing collections of data efficiently and are essential in solving various programming problems.

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