Java Questions

main() method is called by the JVM even before the instantiation of the class, hence it is declared as static.

When an object is passed by value, this means that a copy of the object is passed. Thus, even if changes are made to that object, it doesn’t affect the original value. 

When an object is passed by reference, this means that the actual object is not passed, rather a reference of the object is passed. Thus, any changes made by the external method, are also reflected in all places.

Inheritance is the ability to create new classes based on existing classes. It is useful to reuse existing code.

Executing more than one program simultaniously.(i.e at time)

Ex:

Windows media player  is a program

Internet explorer(IE) is another program executing both the programs  at a time is called multi tasking.

Function: A Function is a block of statement which perform some operation.

Declaring the function before using the function in program is known as implicit declaration of the function.

For Example::

int bar(void); // function (forward) declaration

int main(void) {

bar(); // bar was declared, the compiler has all the info

return foo(123); // foo not yet known; impl. decl. warning

}

// not previously declared function definition

int foo(int a) {

return a;

} 

// previously declared function definition

int bar() {

return 321;

}