Java Programming : Doubts

1.

What is the purpose of using Strings [] args in the following statement, considering that no value is being returned to the main function.

public static void main (String[] args )

and then string [] means a string is being returned, so why the statement args, that too without being separated by comma ?


2. is it possible to have the following for loop like in C/C++


for ( ; condition ; )
{ ..
.. };

Originally Posted by newprouser

1.

What is the purpose of using Strings [] args in the following statement, considering that no value is being returned to the main function.

public static void main (String[] args )

and then string [] means a string is being returned, so why the statement args, that too without being separated by comma ?


2. is it possible to have the following for loop like in C/C++


for ( ; condition ; )
{ ..
.. };

1. public static void main(String[] args) is the method from where your java application begins.
We can have multiple main method but the signature exactly matching to the above method, is recognised by jvm and it starts by calling that main method.
It's like entry point.

The purpose of using String[] args is that, you can provide inputs to your application before actually running it.

String[] args means array of String. Hope you know what array is.

2. Better to check for yourself. In my opinion it should run.

String args[] also.
String... args also. This is called var args.
What nandini had said is right? rep+ to her for beating me to answer.

Originally Posted by nandini

1. public static void main(String[] args) is the method from where your java application begins.
We can have multiple main method but the signature exactly matching to the above method, is recognised by jvm and it starts by calling that main method.
It's like entry point.

The purpose of using String[] args is that, you can provide inputs to your application before actually running it.

String[] args means array of String. Hope you know what array is.

well I have used C/C++ and OOPS in it too.

are you talking about operator overloading in the first para ??

2. Better to check for yourself. In my opinion it should run.

not running. thats why i was wondering if there's any other alternative statement for that.

NPU,

that's the equivalent of main (argc, argv) in C and C++

"String [] args" is the same as "char **argv" or "char *argv[]" for
all practical purposes.

they are the command line parameters when you run the program.

-F

what exactly is not working in your program?

1. It's not operator overloading. in fact java doesn't support operator overloading.

you can declare an array of String in two ways.

String[] arr=null; //more readable
String arr[]=null;

2.I think in for loop initialization is a must. So you can write like
for(int i=0;condition; ) //it should work.
by the way why the hell do you want to write it? Do you want to create infinite loop?

PS: Farce is right,as usual.

Sorry can't rep now, will rep ya ASAIC

Originally Posted by newprouser

Sorry can't rep now, will rep ya ASAIC

It doesn't matter anything to me. What really important is that whether you got your doubt cleared.

Originally Posted by nandini

1by the way why the hell do you want to write it? Do you want to create infinite loop?

break;
goto
return
exit

;-)

and what's wrong with infinite loops?
this is the program that NPU is writing

login to IBF
for ( ;forever; ) {
post :lol:
}

Originally Posted by nandini

PS: Farce is right,as usual.

my online reputation is much better than my domestic one ;-)
I wish you could tell that to my wife ;-)

Originally Posted by farce

NPU,

that's the equivalent of main (argc, argv) in C and C++

"String [] args" is the same as "char **argv" or "char *argv[]" for
all practical purposes.

they are the command line parameters when you run the program.

-F

Originally Posted by nandini

1. It's not operator overloading. in fact java doesn't support operator overloading.

you can declare an array of String in two ways.

String[] arr=null; //more readable
String arr[]=null;

2.I think in for loop initialization is a must. So you can write like
for(int i=0;condition; ) //it should work.
by the way why the hell do you want to write it? Do you want to create infinite loop?

PS: Farce is right,as usual.

thanks both of you , got the first one cleared.

Originally Posted by farce

what exactly is not working in your program?

well i'm not able to create a loop like this in java, atho it will work in C

for ((blank) ; condition ;(blank) )

by the way why the hell do you want to write it? Do you want to create infinite loop?

even god won't know why i'm doing what i'm doing

Originally Posted by farce

break;
goto
return
exit

;-)

and what's wrong with infinite loops?
this is the program that NPU is writing

login to IBF
for ( ;forever; ) {
post :lol:
}



my online reputation is much better than my domestic one ;-)
I wish you could tell that to my wife ;-)

:lol:

nice idea farce, maybe i should use Fx and use a macro with it

---

:lol:

Originally Posted by farce

my online reputation is much better than my domestic one ;-)
I wish you could tell that to my wife ;-)

i'd guess her reply to be "the boss is always right :sneaky2: "

It is working for me:-
class Main {

public static void main(String[] args)
{ int i=1 ;
for ( ;i >0 ; )
{
i=1;
}
}
}

Originally Posted by Luke Skywalker

It is working for me:-
class Main {

public static void main(String[] args)
{ int i=1 ;
for ( ;i >0 ; )
{
i=1;
}
}
}

My bad, i had initialized ch1 as zero, so that was the problem.

public class chaz
{
public static void main (String[] args )
{
char ch1;

ch1=1;

for ( ; ch1 < 127 ; )
{
System.out.println(ch1);
ch1++;
}

}
}

That is also a valid program but it print character upto 127

Originally Posted by Luke Skywalker

That is also a valid program but it print character upto 127

yes, i was trying to print ASCII values, since its from 0-127, i initialized ch1 as 0., which seems to be the cause of the problem.

Post the exception & error you get. They are your best teachers.

Originally Posted by Luke Skywalker

Post the exception & error you get. They are your best teachers.

well well it was for a reason u guys asked me not to use an ide in the beginning, coz the original program (with ch1=0) is working fine in CMD, but in IDE , no output was displayed (except process completed).

Yes it will work. Don't use IDE now. Use cmd only.

Originally Posted by newprouser

well well it was for a reason u guys asked me not to use an ide in the beginning, coz the original program (with ch1=0) is working fine in CMD, but in IDE , no output was displayed (except process completed).

it can't be.
post your code.

Originally Posted by nandini

it can't be.
post your code.

public class chaz
{
public static void main (String[] args )
{
char ch1;

ch1=0;

for (;ch1<127; )
{
System.out.println(ch1);
ch1++;
}

}
}

I use Jcreator Pro IDE. v4.5

Simple suggestion. Can't this be written as follows:

public class chaz
{
public static void main (String[] args )
{
for (ch1=1;ch1<127; ch1++)
{
System.out.println(ch1);
}

}
}

This will be proper and clear way of coding as per the standard followed by many java developers.

Originally Posted by matrix

Simple suggestion. Can't this be written as follows:

public class chaz
{
public static void main (String[] args )
{
for (ch1=1;ch1<127; ch1++)
{
System.out.println(ch1);
}

}
}

This will be proper and clear way of coding as per the standard followed by many java developers.

Sure, I'm a beginner to java.

Originally Posted by newprouser

Sure, I'm a beginner to java.

Well, it is better to follow a standard from the begining. Even I come across many who don't follow any standard. But suggestion is better follow a standard as you are already a C/C++ pro.

Originally Posted by matrix

Well, it is better to follow a standard from the begining. Even I come across many who don't follow any standard. But suggestion is better follow a standard as you are already a C/C++ pro.

oh if i knew i would. thats one disadvantage when one learns from e-books instead of computer courses i guess.

Which book are you using?

Which book are you using?

Java 2 - The Complete Reference 5edition, herbert schildt.

Its outdated, but its the one I found to be easiest.

Head first Java is much easier & you will retain it more.

Head first Java is much easier & you will retain it more.

oh, i plan to use them side by side.

Here is the link for it. You can read it legally Head first Java - Google Books