Difference Between Array and Arraylist

Difference Between Array and Arraylist

In Java,what is the difference between array and arraylist is a very common question. Indeed, those who ask the question are usually programming beginners. Although many people have asked this question for years, more and more people continue to find it difficult to understand. Well, we decided to get involved, thus helping countless number of newbies spot the difference between array and arraylist.

Sincerely, this is understandable given that the two similar roles in storing data. Are you one of those who cannot wrap their heads around the difference between array and arraylist in Java? If yes, you are reading the right piece because this guide breaks down everything you need to know about the two memory locations.

Definition of Array

In C and C++ programming, array is an important component used to store data. However, it tends to be static in nature in this context. Most times, it has a fixed data structure, meaning that once its structure is created, the programmer cannot alter its length. In other words, it serves as a container that holds data that do not change. Once a memory location is declared an array, it means that the space will have to store values of the same type. Technically, the value of the data container must remain constant.

At this stage, the next thing you may be considering is how to access the container. To do that, the numerical index that corresponds to that location of the element in question must be applied. In this case, the numerical index must also be a non-negative value. Given that the opener is zero, you will need an index with value eight to access the ninth element, and it keeps going in that order.

The set of data here could be single dimensional or multidimensional. More importantly, this type of arrangement has both advantages and disadvantages. In summary, you could say that an array, in Java programming, is an object that holds elements of the same data set. With that explained, just before we go ahead with the difference between an array and an arraylist, let’s dissect what the latter is.

Definition of Arraylist

On the other hand, arraylist is a tray that contains variable data set. In this case, the builder of the tray determines how he wants the growth to happen. Upon creating an array, they either grow or shrink. Looking for a created resizable tray, you can find it in Java.util package. This means that the builder can add or remove elements as they please in this context.

Note that the syntax that you use to build this constantly changing data tray is quite different from that of an array. To access an element in the container, you will have to use the command, get (). For instance, you want to get a car, which one of the elements in the tray, here’s what you would key in: car.get (ʘ).  

Array vs Arraylist Comparison Table

Basis of ComparisonArrayArraylist
MeaningA memory space that holds fixed elementsA memory location for holding variable data set
Use of GenericsNot allowed in JavaBuilder can use Generic to determine type safety
Variable DeterminationProvides length variableProvides size variable
Store for primitives Contains both primitives and objectsContains only primitives
Element additionUse of assignment operator for storing data set Use the add () method to populate the tray

Conclusion of the Main Difference Between Array vs Arraylist

At this point, we strongly believe that we have explained the major difference between arraylist and array, thus helping beginners overcome that challenge. In wrapping up this piece, there are other differences that we may have to point out. Looking at their dimensions, while array could be both single dimensional and multidimensional, the other is just single dimensional. Also, we may look at the disparity from the angle of Type Safety.

Although we mentioned in the table, we didn’t lay emphasis on how it plays out in Java. Basically, the scripting language requires data set in Arraylist to guarantee Type Safety. This is not the case with array as it holds elements of the same class. When a programmer tries to store a different object in the tray, ArrayStoreException pops up, which sends a negative signal.

With respect to performance output, the two containers return different operations. Finally, when you wish to iterate content of the tray, you will need an iterator object to do that on arraylist. However, to carry out the same operation on array, you will need a loop. So, we have been able to help you spot the difference between array and arraylist. Make sure you teach those who do not know it!