In java i would like to create a method that can return multiple objects like a couple of int values,  strings, float , double etc. what is the way to do this?
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I want to return two objects from a Java method and was wondering what could be a good way of doing so?  The possible ways I can think of are: return a HashMap (since the two Objects are related) or return an ArrayList of Object objects.  To be more precise, the two objects I want to return are (a) List of objects and (b) comma separated names of the same.  I want to return these two Objects from one method because I dont want to iterate through the list of objects to get the comma separated names (which I can do in the same loop in this method).  Somehow, returning a HashMap does not look a very elegant way of doing so.
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Is it completely against the Java way to create struct like objects?  class SomeData1 {     public int x;     public int y; }   I can see a class with accessors and mutators being more Java like.  class SomeData2 {     int getX();     void setX(int x);      int getY();     void setY(int y);      private int x;     private int y; }   The class from the first example is notationally convenient.  // a function in a class public int f(SomeData1 d) {     return (3 * d.x) / d.y; }   This is not as convenient.  // a function in a class public int f(SomeData2 d) {     return (3 * d.getX()) / d.getY(); }
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I have an array that is initialized like:  Element[] array = {new Element(1), new Element(2), new Element(3)};   I would like to convert this array into an object of the  class.  ArrayList&lt;Element&gt; arraylist = ???;
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What is the most efficient way to write the old-school:  StringBuilder sb = new StringBuilder(); if (strings.Count &gt; 0) {     foreach (string s in strings)     {         sb.Append(s + ", ");     }     sb.Remove(sb.Length - 2, 2); } return sb.ToString();   ...in LINQ?
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Can anyone think of any situation to use multiple inheritance? Every case I can think of can be solved by the method operator   AnotherClass() { return this-&gt;something.anotherClass; }
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Java has a convenient split method:  String str = "The quick brown fox"; String[] results = str.split(" ");   Is there an easy way to do this in C++?
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I want to use a collection initializer for the next bit of code:  public Dictionary&lt;int, string&gt; GetNames() {     Dictionary&lt;int, string&gt; names = new Dictionary&lt;int, string&gt;();     names.Add(1, "Adam");     names.Add(2, "Bart");     names.Add(3, "Charlie");     return names; }   So typically it should be something like:  return new Dictionary&lt;int, string&gt; {     1, "Adam",    2, "Bart"    ...   But what is the correct syntax for this?
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There are situations, where it is practical to have a type-cast return a null value instead of throwing a ClassCastException. C# has the as operator to do this. Is there something equivalent available in Java so you don't have to explicitly check for the ClassCastException?
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It would be very useful to be able to overload the . operator in C++ and return a reference to an object.  You can overload operator-&gt; and operator* but not operator.  Is there a technical reason for this?
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I've been lately trying to learn more and generally test Java's serialization for both work and personal projects and I must say that the more I know about it, the less I like it. This may be caused by misinformation though so that's why I'm asking these two things from you all:  1: On byte level, how does serialization know how to match serialized values with some class?  One of my problems right here is that I made a small test with ArrayList containing values "one", "two", "three". After serialization the byte array took 78 bytes which seems awfully lot for such low amount of information(19+3+3+4 bytes). Granted there's bound to be some overhead but this leads to my second question:  2: Can serialization be considered a good method for persisting objects at all? Now obviously if I'd use some homemade XML format the persistence data would be something like this  &lt;object&gt;     &lt;class="java.util.ArrayList"&gt;     &lt;!-- Object array inside Arraylist is called elementData --&gt;     &lt;field name="elementData"&gt;         &lt;value&gt;One&lt;/value&gt;         &lt;value&gt;Two&lt;/value&gt;         &lt;value&gt;Three&lt;/value&gt;     &lt;/field&gt; &lt;/object&gt;   which, like XML in general, is a bit bloated and takes 138 bytes(without whitespaces, that is). The same in JSON could be   {     "java.util.ArrayList": {         "elementData": [             "one",             "two",             "three"         ]     } }   which is 75 bytes so already slightly  smaller than Java's serialization. With these text-based formats it's of course obvious that there has to be a way to represent your basic data as text, numbers or any combination of both.  So to recap, how does serialization work on byte/bit level, when it should be used and when it shouldn't be used and what are real benefits of serialization besides that it comes standard in Java?
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Is there a function the .NET framework that can evaluate a numeric expression contained in a string and return the result? F.e.:  string mystring = "3*(2+4)"; int result = EvaluateExpression(mystring); Console.Writeln(result); // Outputs 18   Is there a standard framework function that you can replace my EvaluateExpression method with?
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Let's say that you have overridden an object's equals() and hashCode() methods, so that they use the object's fields.  How you do you check if two references are to the same object, ala the stock equals() method?
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Can someone explain this method declaration syntax for me?  In this function, the number of rows of a UIPickerView (slot machine UI on the iPhone) is being returned.  From my understanding, the Method is called 'pickerView', and returns an NSInteger.    It passes in a pointer to the UIPickerview called 'pickerView' ... first, why is the method called the same name as the parameter?    Next there is NSInteger parameter called component that tells us which component we are counting the rows for.  The logic to decide which is in the body of the method.    What is 'numberOfRowsInComponent? It seems to describe the value we are returning, but it is in the middle of the parameters.    - (NSInteger) pickerView:(UIPickerView *)pickerView   numberOfRowsInComponent:(NSInteger)component {     if (component == kStateComponent)         return [self.states count];      return[self.zips count]; }
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When I'm debugging, I often have to deal with methods that does not use an intermediate variable to store the return value :     private int myMethod_1()    {       return 12;    }     private int myMethod_2()    {       return someCall( someValue );    }   Well, in order to recreate a bug, I often have to change values on the fly. Here, I could want to see what happens when myMethode_1 return zero. Same thing for myMethod_2.  Is there a way to do that without modifying the code ? What I would like to do, it's to place a breakpoint on the return line (or on the closing bracket) and type-in a new return value.  Note : I'm using Visual Studio 2005 and Visual Studio 2008.  Thank !
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Assume you have some objects which have several fields they can be compared by:  public class Person {      private String firstName;     private String lastName;     private String age;      /* Constructors */      /* Methods */  }   So in this example, when you ask if:  a.compareTo(b) &gt; 0   you might be asking if a's last name comes before b's, or if a is older than b, etc...  What is the cleanest way to enable multiple comparison between these kinds of objects without adding unnecessary clutter or overhead?   java.lang.Comparable interface allows comparison by one field only Adding numerous compare methods (i.e. compareByFirstName(), compareByAge(), etc...) is cluttered in my opinion.   So what is the best way to go about this?
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How could I go about detecting (returning true/false) whether an ArrayList contains more than one of the same element in Java?  Many thanks, Terry  Edit Forgot to mention that I am not looking to compare "Blocks" with each other but their integer values. Each "block" has an int and this is what makes them different. I find the int of a particular Block by calling a method named "getNum" (e.g. table1[0][2].getNum();
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I want to sort a list of objects of a class by 2 ways. I am able to do custom sort by overwriting the compareTo method.  But I have two lists and I want to sort them differently.  Can I still accomplish this by calling the list.sort() method?  global class myClass implements Comparable{      public integer Total{get;set;}     public integer numOfDays{get;set;}      global Integer compareTo(Object compareTo) {         myClass compareToEmp = (myClass)compareTo;         if (Total == myClass.Total) return 0;         if (Total &gt; myClass.Total) return 1;         return -1;             } }   In the above example, how can I also be able to sort by "numOfDays"?  //UPDATE:  I actually wanted to sort list by single property.   But use different properties to sort different lists.  I ended up adding a new field to my class for sorting purpose.  global class myClass implements Comparable{      public integer Total{get;set;}     public integer numOfDays{get;set;}     public boolean isA {get;set;}      global Integer compareTo(Object compareTo) {         myClass compareToEmp = (myClass)compareTo;         if(isA){          if (Total == myClass.Total) return 0;         if (Total &gt; myClass.Total) return 1;             return -1; }         else{              if (Total == myClass.numOfDays) return 0;         if (Total &gt; myClass.numOfDays) return 1;             return -1;          }            } }