In this article, we will talk about arrays in Java. We will go over some examples to help you understand what an array is, how to declare them, and how to use them in your Java code.

What is an array?

In Java, you use an array to store multiple values of the same data type in one variable. You can also see it as a collection of values of the same data type. This means that if you are going to store strings in your array, for example, then all the values of your array should be strings.

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How to declare an array in Java

We use square brackets [] to declare an array. That is:

String[] names;

We have declared a variable called names which will hold an array of strings.

If we were to declare a variable for integers (whole numbers) then we would do this:

int[] myIntegers;

So to create an array, you specify the data type that will be stored in the array followed by square brackets and then the name of the array.

How to initialize an array in Java

To initialize an array simply means to assign values to the array. Let's initialize the arrays we declared in the previous section:

String[] names = {"John", "Jade", "Love", "Allen"};
int[] myIntegers = {10, 11, 12};

We have initialized our arrays by passing in values with the same data type with each value separated by a comma.

If we wanted to access the elements/values in our array, we would refer to their index number in the array. The index of the first element is 0. Here is an example:

String[] names = {"John", "Jade", "Love", "Allen"};

System.out.println(names[0]);
// John

System.out.println(names[1]);
// Jade

System.out.println(names[2]);
// Love

System.out.println(names[3]);
// Allen

Now that we now how to access each element, let's change the value of the third element. That looks like this:

String[] names = {"John", "Jade", "Love", "Allen"};
names[2] = "Victor";

System.out.println(names[2]);
// Victor

We can also check the length of an array using the length property. Here is an example:

String[] names = {"John", "Jade", "Love", "Allen"};
System.out.println(names.length);
// 4
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How to loop through an array in Java

We can use the for loop to loop through the elements in an array.

String[] names = {"John", "Jade", "Love", "Allen"};
for (int i = 0; i < names.length; i++) {
  System.out.println(names[i]);
}

// John
// Jade
// Love
// Allen

The loop above will print the elements of our array. We have used the length property to specify the number of times the loop is supposed to run.

Conclusion

In this article, we learned how to declare and initialize arrays in our Java code. We also saw how to access each element in the array and how to loop through these elements.

Happy Coding!