Mistake to Avoid When Copying Arrays in Java

Arrays are fundament data structure that we use all the time in programing. They’re really useful for storing and accessing multiple elements of the same type, like a list of numbers or strings. However, simple mistakes while working with arrays can lead to undesired program functionality.

One common mistake when copying arrays in Java is to use the assignment operator (=) to copy an array. For example:

This approach does not actually create a new array; it simply creates a new reference to the same array as the source. Therefore, any changes made to the copy will also affect the source, which may not be what you intended.

To make a true copy of array in Java, you should use one of several methods provided by the Arrays class, such as:

This creates a new array with the same elements as the source array, and any changes made to the copy will not affect the source.

Copying by Looping

Another way to copy arrays is to use a loop to copy each element one by one. While this approach work, it can be more error-prone than using of the methods provided by the Arrays class. Here is an example:

The above example creates a new array that is a copy of an existing array with an additional element added to the end of it. This implementation is efficient as it runs in O(n) time complexity and O(n) space complexity, where n is the length of the nums array.

For further information on the Arrays class in Java, please refer to the official documentation provided by Oracle on their website. Thank you, till next time.