26-03-2012, 01:23 PM
Java Interview Questions & Answers
Java_Interview_QAF.pdf (Size: 47.47 KB / Downloads: 92)
What if the main method is declared as private?
The program compiles properly but at runtime it will give “Main method not public.” message.
If you’re overriding the method equals() of an object, which other method you might also
consider?
hashCode()
What is Byte Code?
Or
What gives java it’s “write once and run anywhere” nature?
All Java programs are compiled into class files that contain bytecodes. These byte codes can be
run in any platform and hence java is said to be platform independent.
Expain the reason for each keyword of public static void main(String args[])?
public- main(..) is the first method called by java environment when a program is executed so it
has to accessible from java environment. Hence the access specifier has to be public.
static: Java environment should be able to call this method without creating an instance of the
class , so this method must be declared as static.
void: main does not return anything so the return type must be void
The argument String indicates the argument type which is given at the command line and arg is
an array for string given during command line.
What are the differences between == and .equals() ?
Or
what is difference between == and equals
Or
Difference between == and equals method
How is it possible for two String objects with identical values not to be equal under the ==operator?
The == operator compares two objects to determine if they are the same object in memory i.e.
present in the same memory location. It is possible for two String objects to have the same value,
but located in different areas of memory.
== compares references while .equals compares contents. The method public boolean
equals(Object obj) is provided by the Object class and can be overridden. The default
implementation returns true only if the object is compared with itself, which is equivalent to the
equality operator == being used to compare aliases to the object. String, BitSet, Date, and File
override the equals() method. For two String objects, value equality means that they contain the
same character sequence. For theWrapper classes, value equality means that the primitive
values are equal.