Here let us c the how a basic java program works
class HelloWorld // here classname is hello world { public static void main(String args[]) { System.out.println("Hello World"); } }
Basic structure of java program is
class classname { public static void main(String args[]) { statement 1;
statement 2;
statement 3;
statement 4;
}
}
WHATEVER I SPECIFIED IN RED COLOR ,IT IS MUST FOR ANY A JAVA PROGRAM.
public: public is an access specifier,it can be available anywhere.
public functions are everywhere available.Jvm can be able to call correspondence
main() function.
static: whenever we mention static keyword ,according to java it can be
called by classname.Static functions are common functions,they can be called
without the helpof object.according to java,JVM can be able to call main function
with the help ofclassname.
void: whenever the main function execution is completed
In c/c++ it has to return a value to the os,since application is directly
interacting with os .If main function is not returning a value ,
the os is unable to understand the program memory and it is ready to clean up .
That's why to cleanthe memory ,main function has to return a value in c/c++.
Best example is,my mom kept food for me,in the middle i went out what should
my mom think ? similarly os also unable to understand .This problem will be
identified at large projects in real time,memory is not handling properly,
that is chance of system performance down.
but in java ,we will go for void after complication of program ,JVM will take care .
so no chance of memory wastage.
main() : main is a name of a function,where program execution is started.
main is the starting point of the program execution and it is ending point
of program execution.
Every program execution is done inside the stack memory.
when main() is started,stack memory is started,when main is completed stack memory
also completed.
