Help using argc/argv in assignment


 
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# 1  
Old 09-12-2014
Help using argc/argv in assignment

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1. The problem statement, all variables and given/known data:
First, create a "hello world" program that prints "Hello World". But NOW, instead use argc to verify that a parameter was given, use argv[1] to display the command line argument back to the user after displaying "Hello". For instance, if I type

./helloWorld Michael
I will see
-----> Hello Michael


2. Relevant commands, code, scripts, algorithms:
We are first asked to create a "hello world" program that simply prints "Hello World"
I typed what was given to me from the assignment:

Code:
#include <stdio.h>

int main (int argc, char *argv[])
{
        char *message = "Hello World!";
        printf("%s\n, message);
        return 0;
}

3. The attempts at a solution (include all code and scripts):
Code:
#include <stdio.h>

int main (int argc, char *argv[])
{
        char *message = "Hello World!";
        printf("%s\n", message);
        
if(argc >= 2, argv)
{
       printf("%s_%s", argv[1])
}
return 0;
}

4. Complete Name of School (University), City (State), Country, Name of Professor, and Course Number (Link to Course):
Western Illinois University(WIU), Macomb(Illinois), USA, Justin EHRLICH, CS410(https://westernonline.wiu.edu/d2l/home/58052)

Note: Without school/professor/course information, you will be banned if you post here! You must complete the entire template (not just parts of it).

I'm pretty stuck. It's not giving me the right output and I don't have any experience using C++. Been trying to modify it all day and can't get any help. I'd appreciate any help at all. Smilie
# 2  
Old 09-12-2014
Code:
#include <stdio.h>

int main (int argc, char *argv[])
{
        char *message = "Hello ";
        printf("%s ", message);

if(argc == 2)
{
       printf("%s!\n", argv[1]);
}
else
{
        printf ("world!\n");
}

return 0;

}

This User Gave Thanks to blackrageous For This Post:
# 3  
Old 09-12-2014
Another way:

Code:
int main(int argc, char *argv[])
{
        char *message="Hello";
        char *who="World!";
        if(argc == 2) 
        {
                who=argv[1];
        }

        printf("%s %s\n", message, who);
        return(0);
}

This User Gave Thanks to Corona688 For This Post:
# 4  
Old 09-12-2014
Quote:
Originally Posted by blackrageous
Code:
#include <stdio.h>

int main (int argc, char *argv[])
{
        char *message = "Hello ";
        printf("%s ", message);

if(argc == 2)
{
       printf("%s!\n", argv[1]);
}
else
{
        printf ("world!\n");
}

return 0;

}

Thank you my friend. This works. The only thing that did not work is the part I bolded in the quote. It keeps printing "n" at the end of the statement instead of doing a new line(which is what I think you're trying to do here?). It's not a big deal because I can cut out that part and get the right output anyway.

---------- Post updated at 01:12 PM ---------- Previous update was at 01:10 PM ----------

Quote:
Originally Posted by Corona688
Another way:

Code:
int main(int argc, char *argv[])
{
        char *message="Hello";
        char *who="World!";
        if(argc == 2) 
        {
                who=argv[1];
        }

        printf("%s %s\n", message, who);
        return(0);
}

Thanks for the alternate solution. Gives me something to think about as well.
# 5  
Old 09-12-2014
Quote:
Originally Posted by miniviking10
Thank you my friend. This works. The only thing that did not work is the part I bolded in the quote. It keeps printing "n" at the end of the statement instead of doing a new line(which is what I think you're trying to do here?).
That's exactly what "\n" does inside a double-quoted string, yes.

Did you alter it in any way or double up the backslashes, etc? It really ought to work as-is.
# 6  
Old 09-12-2014
Quote:
Originally Posted by Corona688
That's exactly what "\n" does inside a double-quoted string, yes.

Did you alter it in any way or double up the backslashes, etc? It really ought to work as-is.
It works when I just use the command as "./helloWorld" ...but when I use "./helloWorld John" , it outputs: "Hello John!n" and yea, I definitely have it exactly as you put it. Didn't alter it.
# 7  
Old 09-12-2014
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