CODEWITHSUNDEEP
java
theJava
theJava

Reputation: 15034

Adding and removing properties from java object

How can i achieve this in java. i have an object which has properties.

public class Object {

    private final Credentials Credentials;
    private final int PageSize;
    private final int PageStart;
    private final int DefaultFilterId;

    public Object(Credentials Credentials, int PageSize, int PageStart, 
int DefaultFilterId) {
            this.Credentials = Credentials;
            this.PageSize = PageSize;
            this.PageStart = PageStart;
            this.DefaultFilterId = DefaultFilterId;
       }

    }

Now i am forming a this object like this

Object obj = new Object(args);

At some point i need the same Object, with new properties added but removing some.

I do something like this in javascript. 

var myCars=new Array();
myCars[0]="Saab";
myCars[1]="Volvo";
myCars[2]="BMW";

delete myCars[1]; or myCars.splice(1,1);

Upvotes: 4

Views: 25411

Answers (4)

Guillaume
Guillaume

Reputation: 22822

public class Object {

    private Credentials credentials;
    private int PageSize;
    private int PageStart;
    private int DefaultFilterId;

    public Object(Credentials credentials, int PageSize, int PageStart, int DefaultFilterId) {
        this.credentials = credentials;
        this.PageSize = PageSize;
        this.PageStart = PageStart;
        this.DefaultFilterId = DefaultFilterId;
    }

    // do that for the properties you want to be able to modify
    public void setCredentials(Credentials newCredentials) {
         this.credentials = newCredentials;
    }

}

And you use that:

object.setCredentials(yourNewCredentials)

Also, you shouldn't name your object "Object", it's the base class for all the classes in Java.

Upvotes: 1

PermGenError
PermGenError

Reputation: 46408

put all your instances of your object in a collection, and then you can delete it from the collection.

List<YourObject> list = new ArrayList<YourObject>();
YourObject obj1 = new YourObject("abc");
list.add(obj1);
YourObject obj2 = new YourObject("xyz");
list.add(obj2);

now both your objects are inside a list . later you can use the remove method an remove them. 

 list.remove(obj1);

and just a pointer, its a bad practice to name your class as Object as all java classes extend from java.lang.Object.

Upvotes: 3

bidifx
bidifx

Reputation: 1650

You could add an ArrayList as private property to your class. And than build access-functions that allow you to add and delete entries. You can't do it exactly like in JavaScript.

Upvotes: 1

Chuidiang
Chuidiang

Reputation: 1055

You can´t do that in java. The best approximation is to use HashTable or similar.

Hashtable ht = new Hashtable();
ht.put("key", value);

Upvotes: 1

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