In the Java collections framework, the Collection interface declares the following method:
T[] toArray(T[] a)
"Returns an array containing all of the elements in this collection; the runtime type of the returned ... |
In python you can use a tuple in a formatted print statement and the tuple values are used at the indicated positions in the formatted string. For example:
>>> a = ...
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In the answers here lately, I found some different habits (or flavours). So I wonder when and why is the use of Java's System.arraycopy(...) preferable to something like Collection.addAll(...)? When not?
Edit: ... |
I want to use a collection in place of 2D array so that I don't need to give its size at the time of declaration and I can add as many ... |
I have a task, which I was able to do with the use of simplest methods - arrays. Now I'd like to go further and redo it using some more complicated ... |
Possible Duplicate:
What’s the reason I can’t create generic array types in Java?
HashSet<Integer>[] rows = new HashSet<Integer>[9];
gives me a compilation error: generic array creation.
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Suppose we have a Collection<Foo>. What is the best (shortest in LoC in current context) way to transform it to Foo[]? Any well-known libraries are allowed.
UPD: (one more case in this ... |
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I've found plenty of entries here that say
someFunc(new int[]{1,2,3});
works for calling methods and being used in a for/each loop.
//======
How about for assignment into a collection?
I've tried this:
ArrayList<int[]> data = new ...
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I'm supposed to implement a bag data structure (also called a multiset), an unordered
collection of homogeneous values (any Java object, excluding null) that may have duplicates, for a project. I've done ... |
People say that asList method convert the array into list and its not copying, so every change in 'aList' will reflect into 'a'. So add new values in 'aList' is illegal, ... |
So there's Arrays.asList(T... a) but this works on varargs.
What if I already have the array in a T[] a? Is there a convenience method to create a List<T> out ... |
Since ArrayDeque class implements Deque and since it doesn't have any capacity restrictions.
What is the purpose of Exception throwing methods like addFirst(), addLast(), etc? It will add the elements in ... |
We are learning about the Collection Interface and I was wondering if you all have any good advice for it's general use? What can you do with an Collection that you ... |
i dont quite understand by the given eg on opencsv site on how to use collection here List,eg is:
CSVReader reader = new CSVReader(new FileReader("yourfile.csv"));**
List myEntries = reader.readAll();**
I tried accessing a ... |
is it possible to pass an arraycolelction object from flex ExternalInterface.call() as a parameter to jacascript function?
sample code::
flex
var obj:Object = new Object();
obj.id = "Id";
...
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Hi there I have a question , should one genralize the retun type of Objects by using a collection or just return an array of those objects ? (A) Interface boo{ List something(); } (B) Interface boo{ FooBar[] something(); } I would like to know which one of the options do you guys prefer and why? the way i see it, ... |
I heard this forum was an great site for beginners as myself, thank you in advance for anyone who helps out. I have recently migrated from 20 years of as400/RPGIV/ILE programming to Java. One project involves displaying real-time attributes of service-type people stored on the AS/400 in a *USRSPC(UserSpace). When a user signs on, they get a 277-byte chuck of that ... |
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An array isn't a Collection. What you put into a collection is a reference to an object; if you put primitives in them, you would end up with pointers to incorrect memory locations. It would be impossible to distinguish 123456 representing a memory location from 123456 the number when values are retrieved from a collection. Boxing which you allude to only ... |
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In several circumstances I want to pass a collection of objects around to class methods, e.g. collections of some business objects or a collection of objects where each object should be added to the available objects of a script. Map? Set? Or is an array best to use? - In reality I do not like to use arrays if it is ... |
Well, tehere's nothing wrong. It compiles. The only thing, if you want to see the element in position 5 too you have two options: - a. worst one: in the for, put 6 instead of five in "i<5", so it will show the 5th position. So it would be for (int i = 0; i < 6; i++) - b. best ... |
There is no standard API to convert an array of objects into an array of primitives. How exactly should null values be mapped to primitive values? Should they be disregarded, set to 0 or some other arbitrary value? My advice would be to overload the method comChIndex() which takes an array of Doubles, copy the elements into an array of doubles ... |
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First of: none of those examples compile, it's "toArray" and not "toarray". Second: read the documentation of toArray() (the one without parameters). It will always return an Object array (the content will be MyObject or whatever, but the array itself will be of type Object[]). That's why you have to pass in a correctly-typed array to the one-argument version of toArray ... |
Hi Guys I just wanted to gather some opinions on function returns. Do you think its better to return a Collection or an Array? What are the advantages / disadvantages of each? If you were building a mid sized application for your organization, would you go for a Collection of Array. eg Your DAO has a method called listAllTasks, should this ... |
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I am trying to use JAXB to generate the required setters for Spring beans. Although according to the book Java & XML Data Binding Chapter 3 page 42 by Brett McLaughlin it was possible with DTD's using to generate an array as in public Movie[] getMovie( ) { ... |