Thread: Help a rookie

There is no any loop.You read always the first element of the word

#include <stdio.h>
#define MAXLINE 100
main()

{

int i;
char line[MAXLINE];
for(i=0;i<MAXLINE;i++)
line[i] = getchar ();


printf("&#37;s, its hex character is %3x\n", i);
}

Also you try print a string without palacing at printf and you print i which is a number only.
CAn you explain what hex is?

Originally Posted by ch4

There is no any loop.You read always the first element of the word



Also you try print a string without palacing at printf and you print i which is a number only.
CAn you explain what hex is?

humm ok this is starting to make sense now,

this is the thought i follow when it comes to 'for' loops:

for (initialisation; condition; iteration) command;


so if i understand it right I want to loop through the characters as mike is also saying.

Code:

#include <stdio.h>
#define MAXLINE 100
main()

{
   
   int i;
   char line[MAXLINE];	

   for ( i=1;i<=100;i++)
   line[i] = getchar ();

    
    printf("its hex character is &#37;3x\n", line[i]);
    getchar();    
}

but now it's not outputing anything, what's wrong with my comand? i think my initialisation; condition; iteration are correct ?

example
hence the hex character of J is 4A
so my input is J and it outpus 4A

thanks fort the help so far

Now you are looping a hundred times, getting a character each time. This means the user would have to enter 100 characters.

Instead use a method to get a string such as fgets(). Example:

Code:

#include <stdio.h>
#define MAXLINE 100
int main()
{
   int i=0;
   char line[MAXLINE];	
   fgets(line, MAXLINE, stdin);
   printf("The string &#37;s has a hex value of: ", line); 
   while(line[i] != '\0')
   {
       printf("%3x ", line[i]);
       i++;        
   }    
   getchar();    
}

[edit] Basically you want to be looping through the characters to convert, not the characters that the user enters. Oh yeah something I overlooked: You should use

Code:

int main()

not

Code:

main()

[[/edit]

Always use fgets() in place of gets().

Also, if you feel the need to write random code, look up a tutorial or something on the subject that you're writing for.

i like that function fgets() i see it is used a lot to read characters and input, i came across a getline() it was said that it can do the same, i wanted to implement this using the same idea mike and is not quite working, what can change about my code to correctly implement this idea, I tried getline by itself and i can use it to count characters. Can this be done ? I know fgets() works but i need to learn more since i am quite new at this.

Code:

#include <stdio.h>
#define MAXLINE 100
int main()
int getline (char s[], int maxline);

{ 
   int i=0;
   char line[MAXLINE];	
   getline(line, MAXLINE, stdin);
    
   printf("the string &#37;s has a hex character of: ", line);
   while (line[i] != '\0')

    {
	printf("%3x", line[i]);
	i++;
    }

    getchar();
    
}

int getline (char s[], int maxline)

{ 
	int c, i;
	for ( i=0; ( c=getchar() ) != EOF && c!='\n'; ++i) 
	s[i] = c;

	if ( c =='\n') {
		s[i] = c;
		++i;
	}
	
	s[i] = '\0';

	return i;
}

c:4 error: declaration for parameter "getline" but no such parameter
c:9 error: too many arguments to function

Don't write these functions if you don't know what you're doing. You have to break down the problem to very small parts.

Simple version of getline() I wrote just now for you:

Code:

char *getline(char *szBuffer, size_t stLen)
{
	size_t i;
	int c;
	for(i=0;i<stLen;i++)
	{
		c = fgetc(stdin);
		if(c == EOF)
		{
			return NULL;
		}
		else if(c == '\n')
		{
			return szBuffer;
		}
		szBuffer[i] = c;
	}
	return szBuffer;
}

First problem is that you're not using maxline at all. You just keep writing, and writing, and writing, and you'll overrun your block of memory if the user keeps typing.

In terms of calling the function, look at the arguments that getline() accepts. Look at what you're passing it. See a conflict?

*cough*int main*cough*

your printf tries to print element 5 which is out of bounds array
BTW indexes of the array go from 0 to 4 so even your for is buggy