-
What is the difference between Assertion and Exception?
raghuprasad
- Aug 25th, 2008
There is no concept called Assertion present in Java. Exception is the program error which arises due to uncontrolable condition. This condition can be arised automatically from to program code(Eg. Da...
raj_sharma
- Aug 22nd, 2008
Exception is a mechanism used by many programming language to describe what to do when something unexpected happens.Assertion is the way to test the certain assumptions about the logic of your program.
-
Can we declare multiple main() methods in multiple classes.ie can we have each main method in its class in our program?
r.praveenkumar
- Aug 6th, 2008
Yes I tested this we can have main method in two different classes this will not give error and we should save that doc with the class name which has the main we want to be executed first and inside t...
vinaymudgil007
- Jun 3rd, 2008
Yes this is possible...... but within a single file only one class can be declared puiblic!!!!and whichever class you run, that class's main() mentod would be called.......vinny
-
What is the use of writing empty catch block?
vinaymudgil007
- Jul 31st, 2008
Just catch the exception & swallow it [don't take any action].that's all.vinay
-
When you use a struts framework, where would you place your business logic
Debananadajena
- Jul 16th, 2008
When we are using struts the action class should not contain the business logic if we are adding in action class then it is not right because action class are instantiated by controller.So we can use ...
shaik subhani
- Dec 18th, 2007
When we want to develop complex applications , you can use struts framework.Strtus framework is based on MVC architecture. Actually we have model classes to develop businesslogic .you can access model classes from execute() method of Action class
-
What is heap in Java
Debananadajena
- Jul 16th, 2008
HiHeap is the location where a object is stored after it is instansiated.Means after A obj=new A();now obj will be storeed in heap.
sampra
- Feb 22nd, 2008
It is a memory area which stores all the objects created by an executing program.
-
JSP Paging
Hi.. I have developed one web-page which shows ALL employee records fetched from a employee table and display them in my JSP page.It has contain more than 1000's of records. I need to display first 10 Records in my page. There should be some 4 links below the records display which get me to see next 10 records or previous 10 records or first 10 records or Last 10 records. IS it possible in JSP?? Can...
mini2008
- Jul 14th, 2008
Paging In JSP Page:--------------------------1. Change Your SP which is going to retrieve data by adding 2 more columns CurrentPage,DisplayCount and the usual other Parameters that u have ...
-
What is the difference between core java and advanced java
Naveenjavasun
- Jul 8th, 2008
According to sun system there is no corejava and advanced java.only j2se,j2eeNo advanced java is there as per sun micro... Fucking Training centers daivide j2ee into two patrs. Dont tell in interview i Know Advanced Java.
satheeshraja
- Jun 20th, 2008
1. In core Java, we dont have any solutions for dynamic process but still core java is a very efficient for developers and this is the strong basement for applications.2. Advanced Java has complete s...
-
In overriding, the super class method throws I/O exception & in sub class that method throws arithmetic exception. what happens?
R.Raj
- Jul 5th, 2008
Hi Amit,Actually in overriding there are some rules need to be follow.Overriding means the method with same signature as the super class,and signature means the name of the method,number of argum...
abdul khalik
- May 22nd, 2006
program will work fine Example:-/* * OverSuper.java * *Created on May 22, 2006, 12:11 PM *Concept: overriden method can throw diffrent exceptions *its method will be override...
-
What is the difference between an instance and an object in Java?
raghavleo
- Jul 4th, 2008
In general we think instance and objects are same, but they are incorrect.instance will have the both class definiation and the object defination where as in object it will have only the object defina...
AjayMukiri
- Apr 30th, 2008
Instance and Object are same as per my knowledgeCreating an Instance of a class is creating an object onlyA a = new A() --Here "a" is an instance of a class A, on same time "a"...
-
Difference between throw and throws
What exactly is the difference between between throw and throws? If both are used for the same purpose then why are both needed instead of one?
Read Best Answer
Editorial / Best Answer
vegetto- Member Since Jun-2008 | Jun 15th, 2008
hi there,
throw:the throw keyword is used to throw the exception manually,that is when you feel a particular line in your code, when executed is capable of having some exception then you use throw keyword as:
throw new MyException(arguments if any);
this leads to instantiating of the MyException class and exception is thrown
throws: this is to be used when you are not using the try catch statement in your code but you know that this particular class is capable of throwing so and so exception(only checked exceptions).in this you do not use try catch block but write using the throw clause at appropriate point in you code and the exception is thrown to caller of the method and is handeled by it. eg:
void trouble()throws IOException,any other exceptions just separate them with commas.......
{
/* throw statement at appropriate step,
no need to use try catch here,exception would be thrown to caller and u should provide try catch block to handle exception there else this process cotinues further till
appropriately it is handeled or prog terminates abruptly */
}
this is called as HANDLE OR DECLARE RULE i.e either u handle exceptions using try catch block or by declaring them
vegetto
- Jun 15th, 2008
hi there, throw:the throw keyword is used to throw the exception manually,that is when you feel a particular line in your ...
krishna_kanth83
- Jun 14th, 2008
they are not same."throws" declares that your method is capable of throwing an exception."throw" actually does the work , of throwing the exception.example :public void...
-
//this.disp();
}
void t3()
{
System.out.println("Enter to t3 void");
}
}
On what situation void type constructors are used?">Class t3{ int i; static public void main( String a[]) { int j=8; t3 t= new t3(); new t3().disp(j); } //constructor overloading t3() { System.out.println("Enter to t3"); //this.disp(); } void t3() { System.out.println("Enter to t3 void"); }}On what situation void type constructors are used?
vinaymudgil007
- Jun 12th, 2008
Constructor's don't have any return-type....... and hence when you precede void with constructor java comipler treats it as a METHOD of that class and not as constructor!!!vinny
chinnu
- Nov 18th, 2006
Actually constructor means one type of special methods in java. It returns nothing even void also. These are used for intilising the objects with same parameters and different parameters.
-
Name two classes that can store arbitrary number of objects
vinaymudgil007
- Jun 12th, 2008
This is one of the resons we have Collections framework in javaexamplesArrayList , Vector , Set -- directly as objectsHashTable, HashMap -- as objects as ket-value pairsvinny
Amit Rastogi
- Oct 5th, 2006
Any collection which is not having singleton or unmodifieable modifier can store any no of objects
-
Hi, can we declare non static variables in static methods?if so plz explain by an example?
vinaymudgil007
- Jun 12th, 2008
yes, we can declare and they would be local to the block.Here is an example.....class Test { public static void main(String[] args) { ...
Seema
- Feb 2nd, 2007
Declaration of i is outside static method, so it is giving error "can not make static reference to non static field" if it is declared inside then it will print 10.
-
Can i write marker interfaces,if yes how can i?
vinaymudgil007
- Jun 12th, 2008
Yes you can write marker interface.A marker interface is the one which doesn't have any methods declared in it e.g. Serializable etc.Here you go as marker interface...............interface thisIsAMarkerInterface{ }vinny
shashidhar reddy
- Dec 1st, 2006
Hi Sunil, can u briefly explain this.Is it possible to write userdefined marked interfaces &...
-
Static methods are override or overload ?
vinaymudgil007
- Jun 12th, 2008
Guys to my knowledge..... we can overload but can't override static methodsvinny
-
How to call a static block in one class from another class?. And is it possible to call a free floating block in one class from another class?. How?
vinaymudgil007
- Jun 11th, 2008
static block gets executed whenever is class is loaded by the JVMso what you can do is.....write is class having static block in it ---> compile it --> write another class (ensure that fir...
NavaNani
- Apr 7th, 2008
Non static blocks & Static blocks are executed one by one by the order of their defintion before any constructor is being executed.Static blocks can also be invoked without creating instance ...
-
1)what happens if i do this=null?2)how to swap 2 variables without using third temp variable in java?3)constructors can not be inherited,why?
vinaymudgil007
- Jun 10th, 2008
The answer given above by Mr. Satish------------------------------------------------------------------------------------------a= ((a+b)-(a-b))/2b= ((a+b)+(a-b))/2--------------------------------------...
-
What is the difference between the public access modifier and default access modifier?
Santosh N
- Jun 11th, 2008
Any attribute or method with default access modifier can be accessed from other classes or methods only within the same package whereas any attribute or method with public access modifier can be accessed from anywhere in the application.
JIGAR
- Sep 14th, 2006
classpublic class can be accessed from any other classes... its public to whole java universe... where as default is package level access... if the sub class is in diff package and is default th...
-
What is data object?
vinaymudgil007
- Jun 10th, 2008
Boss..... the question isn't clear!! im not sure if we have some trminology as "data object".please elaborate
-
What is serialization?What is transient?What is the default value of a transient variable?
vinaymudgil007
- Jun 10th, 2008
serialization -- means saving the state of an object at a particalar instance of time.transient -- appended before a variable to ensure that the valiable is not saved during serailizationdefault value -- well, that has nothing to do with serailization, it depends on the data type of the variable
Ganesh Bala Kumar
- Aug 14th, 2006
Hi,State is nothing but the present values of the class level variables and behaviour (methods) of the class.Suppose if u r having setters and getters in ur class , when u retrieve the values into the...
Core Java Interview Questions
Read Best Answer
Ans