Comparing functionality between Vectors and Arrays in Java

I've been thinking about this one f开发者_Python百科or a long time. What is the difference between Vectors and Arrays? I know they do similar things, if not exact.

String Array

String[] array = new String[4];

String Vector

Vector<String> vector = new Vector<String>(4);

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It seems kind of redundant to me why there would be both arrays and vectors. Are there any advantages or disadvantages to using one or the other?

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Vectors are resizable. Arrays are not.

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The difference is that 'Vector' is an extension by programmers, whereas an array is a built-in function of the language itself.

You can edit how the Vector behaves (by editing its source code), whereas an array is defined by the compiler.

And obviously, Vectors can be potentially sized (depending on implementation). Arrays are static and cannot be resized - you have to recreate it and copy the data over.

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Vector is synchronized. Arrays are not(?).

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Array cannot be re-sized, while Vectors can.

Vector uses Arrays internally. The main advantage of a Vector compared to an Array is its automatical increase of capacity. An Array keeps its size once created, a Vector does not

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It seems kind of redundant to me why there would be both arrays and vectors

For one, Vectors can be resized. If you declare an array of size 10, you are left with 10 always, unless you copy the contents to another larger sized array. Methods of Vector are synchronized.

Vectors are part of the collections framework. Vector is a List. There are other lists, ArrayLists, LinkedLists etc with specific features. There are Sets and Maps. All of them hold "lists" of items, but each of them give specific advantages in specific situations.

You might want to read about java collections.

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Vectors will automatically resize for you to accommodate as many entries as you want in them. An array is fixed in size, and will give you an OutOfBounds exception when you try to add more than you allocated.

When you provide the size for a vector, that's just the original size it starts with. It'll automatically grow/shrink as necessary.

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1- Vectors are resize-able, arrays are not

2- Vectors are responsible for memory allocate and release, arrays are not. This makes vectors safer to use than arrays.

3- Vectors have a good performance on their implemented functions, which you may not reach by your own programming with arrays.

4- Finally I think it's wiser to use vectors, most of the times.

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An array is a basic java data structure, whose size is fixed when defined.

A Vector is part of the Java Collections Framework, and contrary to your beliefs, or not even close to the same thing as an array. Among many other things, Vectors are resizable and can interact with other collections.

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Java array types are not necessary. They actually create a lot of problems. Avoid them if you can.

We could do better to replace them with a standard class Array<T>. Some new post-Java languages are taking this approach.

(History alert) In the old days, Java didn't have generics, a non-generic collection class would suck to use (with lots of castings). Then array types were really poor man's generics because they carry element type info. That's why many methods return arrays, instead of List.

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I think the above suggestion is not good. Check this link to get brief idea. Difference b/w Array and Vector

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Vectors help to insert and delete elements easily while arrays helps to sort and access elements with ease.

Vectors can hold different type of elements Arrays only the type defined when forming them

You can use array list which is some what similar to vector and provided much better features