Arrays in java introduction

Lecture 44:- Arrays in java introduction

In Java, an array is a data structure that allows you to store a fixed-size collection of elements of the same data type. Arrays provide a convenient way to group multiple related values under a single variable name and access them using an index. The index starts from 0 and goes up to the size of the array minus one.

To use arrays in Java, you need to declare the array variable and initialize it with the desired number of elements. Here's the basic syntax to declare and initialize an array in Java:

javaCopy code
dataType[] arrayName = new dataType[arraySize];

• dataType: The data type of the elements to be stored in the array.
• arrayName: The name of the array variable.
• arraySize: The number of elements the array can hold.

Once you have created an array, you can access and modify individual elements using their index. Array indices start from 0, so the first element is accessed using index 0, the second element with index 1, and so on.

Here's an example of how to declare, initialize, and use an array of integers in Java:

javaCopy code
public class ArrayExample {
    public static void main(String[] args) {
        // Declare and initialize an array of integers
        int[] numbers = new int[5];

        // Assign values to the array elements
        numbers[0] = 10;
        numbers[1] = 20;
        numbers[2] = 30;
        numbers[3] = 40;
        numbers[4] = 50;

        // Access and print array elements
        System.out.println("First element: " + numbers[0]);
        System.out.println("Second element: " + numbers[1]);
        System.out.println("Third element: " + numbers[2]);

        // Modify an array element
        numbers[3] = 45;

        // Calculate the sum of all elements
        int sum = 0;
        for (int i = 0; i < numbers.length; i++) {
            sum += numbers[i];
        }

        System.out.println("Sum of all elements: " + sum);
    }
}

Output:

yamlCopy code
First element: 10
Second element: 20
Third element: 30
Sum of all elements: 155

In the example above, we declare an array of integers named numbers with a size of 5. We then assign values to each element using the index. We access and print individual elements using their respective indices. We also modify one of the elements by updating its value. Finally, we calculate the sum of all elements using a for loop that iterates through the array.

Arrays are a fundamental concept in Java and are used extensively in various applications to store and manipulate collections of data efficiently.

Disclaimer:-

Under Section 107 of the copyright act 1976, allowance is made for fair use for purposes such as criticism, comment, news reporting, scholarship, and research. Fair use is a use permitted by copyright statute that might otherwise be infringing. Non-profit, educational, or personal use tips the balance in favor of fair use.