How Do `equals()` and `Arrays.equals()` Differ When Comparing Arrays in Java?

Equals vs. Arrays.equals in Java

When dealing with arrays in Java, understanding the differences between the equals and Arrays.equals methods is crucial to ensure accurate array comparisons.

array1.equals(array2)

This expression compares the reference equality of the two arrays. In other words, it checks if array1 and array2 are the same array object, regardless of their content. While this behavior might align with expectations, it's important to note that it performs a shallow comparison, comparing the memory addresses of the arrays rather than their actual values.

Arrays.equals(array1, array2)

In contrast, Arrays.equals(array1, array2) performs a deep comparison of the arrays' content. It iterates through each element in both arrays, comparing them for equality. This method returns true if all the corresponding elements are equal, otherwise it returns false.

For example, consider the following arrays:

int[] array1 = {1, 2, 3};
int[] array2 = {1, 2, 3};

Using array1.equals(array2) would return false because they are different array objects, while Arrays.equals(array1, array2) would return true because they have the same content.

Similarly, the toString() method applied to an array might not provide the desired output. Consider this code:

int[] array3 = {4, 5, 6};
System.out.println(array3.toString());

This would print "[I@1873311", which represents the memory address of array3. Instead, using Arrays.toString(array3) would output "[4, 5, 6]", providing a more informative representation of the array's content.

Understanding the distinctions between equals, Arrays.equals, and toString() is essential for accurate and efficient array handling in Java.

The above is the detailed content of How Do `equals()` and `Arrays.equals()` Differ When Comparing Arrays in Java?. For more information, please follow other related articles on the PHP Chinese website!