Introduction to Arrays

Arrays are an essential data structure in programming. They allow you to store multiple values of the same type in a single variable. Arrays provide a way to efficiently organize and access data.

Array Declaration and Initialization

To declare and initialize an array in Java, you can use curly braces {} to specify the values.

Here's an example:

1// Array declaration and initialization
2int[] nums = {1, 2, 3, 4, 5};

In this example, we have declared and initialized an array nums containing the integers from 1 to 5.

Accessing Elements of an Array

You can access individual elements of an array using square brackets [] and the index of the element. Array indices start at 0.

Here's an example:

1// Accessing elements of an array
2System.out.println(nums[0]); // outputs 1

In this example, we are accessing the first element of the nums array, which is 1.

Modifying Elements of an Array

You can modify the value of an element in an array by assigning a new value to the specific index.

Here's an example:

1// Modifying elements of an array
2nums[3] = 10;

In this example, we are modifying the value at index 3 of the nums array and assigning it a new value of 10.

Array Length

You can determine the length of an array using the length property.

Here's an example:

1// Array length
2int length = nums.length;

In this example, we are storing the length of the nums array in the variable length.

Looping Through an Array

To iterate over all the elements of an array, you can use a loop. A common loop used for this purpose is the for loop.

Here's an example:

1// Looping through an array
2for (int i = 0; i < nums.length; i++) {
3  System.out.println(nums[i]);
4}

In this example, we are using a for loop to iterate over each element of the nums array and printing the value.

Arrays are a fundamental concept in programming, and understanding how to work with arrays is crucial for solving many programming problems.

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class Main {

  public static void main(String[] args) {

    // Array declaration and initialization

    int[] nums = {1, 2, 3, 4, 5};

    // Accessing elements of an array

    System.out.println(nums[0]);

​

    // Modifying elements of an array

    nums[3] = 10;

​

    // Array length

    int length = nums.length;

​

    // Looping through an array

    for (int i = 0; i < nums.length; i++) {

      System.out.println(nums[i]);

    }

  }

}