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Mar 30th, 2005

strings as input, substr and len

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i'm currently writing a program that needs one small piece in my opinion in order to work. i have an array which reads in a bunch of numbers (call them addresses, an example is "003124") and counts the amount of addresses at the moment. i need this to be passed into a switch statement that does certain things for each number in each address, i've written a mix of code/pseudocode

C++ Syntax (Toggle Plain Text)
entil EOF do;
        string = input;
        len = length(string);
          for i=1 to len do
              ch = substr(string, i-1, 1)
                switch(ch)
                 //case statements
entil EOF do;
        string = input;
        len = length(string);
          for i=1 to len do
              ch = substr(string, i-1, 1)
                switch(ch)
                 //case statements

i want each "string" in the input to be a single address. does anyone know how to do this? i'll provide more information if needed.
thanks in advance.

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rborob

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Mar 30th, 2005

Re: strings as input, substr and len

First, I have grown to hate the "while not at end of file" stuff; I now prefer "while successfully obtaining the data I request from the file" approach. Anyways, here is a possible starting point.

C++ Syntax (Toggle Plain Text)
/* file.txt
003124
*/
#include <iostream>
#include <fstream>
#include <string>
 
int main ()
{
   std::ifstream file("file.txt");
   std::string input;
   while ( std::getline(file, input) )
   {
      for ( std::string::size_type i = 0, len = input.size(); i < len; ++i )
      {
         switch ( input[i] )
         {
         case '0': std::cout << "zero"  << '\n'; break;
         case '1': std::cout << "one"   << '\n'; break;
         case '2': std::cout << "two"   << '\n'; break;
         case '3': std::cout << "three" << '\n'; break;
         default:  std::cout << "other" << '\n'; break;
         }
      }
   }
   return 0;
}
 
/* my output
zero
zero
three
one
two
other
*/
/* file.txt
003124
*/
#include <iostream>
#include <fstream>
#include <string>

int main ()
{
   std::ifstream file("file.txt");
   std::string input;
   while ( std::getline(file, input) )
   {
      for ( std::string::size_type i = 0, len = input.size(); i < len; ++i )
      {
         switch ( input[i] )
         {
         case '0': std::cout << "zero"  << '\n'; break;
         case '1': std::cout << "one"   << '\n'; break;
         case '2': std::cout << "two"   << '\n'; break;
         case '3': std::cout << "three" << '\n'; break;
         default:  std::cout << "other" << '\n'; break;
         }
      }
   }
   return 0;
}

/* my output
zero
zero
three
one
two
other
*/

Dave Sinkula

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long time no c

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Mar 30th, 2005

Re: strings as input, substr and len

>I have grown to hate the "while not at end of file" stuff
Me too. Mostly because in C and C++ it's a subtle and dangerous error.

Narue

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Mar 31st, 2005

Re: strings as input, substr and len

ok well since i've counted all the addresses in a previous function call it EOF or "while count < Number of addresses". thats not the part thats bothering me. the purpose of the switch statements is to set up a couple of variables, say xCount YCount and zCount and the case statements will increment 1,2 or all 3 of these depending on the number found. then be able to store these in an array. like so

C++ Syntax (Toggle Plain Text)
		switch(addresses[i])
		{  
		default: //  don't do anything
		break;
 
		case '0':
				break;
 
		case '1': xCount++;
				break;
 
		case '2': yCount++;
				break;
 
		case '3': xCount++;
				  yCount++;
				break;
 
		case '4': zCount++;
				break;
 
		case '5': xCount++;
				  zCount++;
				break;
 
		case '6': yCount++;
				  zCount++;
				break;
 
		case '7': xCount++;
				  yCount++;
				  zCount++;
				break;
		}
		xCount = g_pVertices[index].x;
		yCount = g_pVertices[index].y;
		zCount = g_pVertices[index].z;
		index++;
	}
}
		switch(addresses[i])
		{  
		default: //  don't do anything
		break;

		case '0':
				break;
		
		case '1': xCount++;
				break;

		case '2': yCount++;
				break;

		case '3': xCount++;
				  yCount++;
				break;

		case '4': zCount++;
				break;

		case '5': xCount++;
				  zCount++;
				break;

		case '6': yCount++;
				  zCount++;
				break;

		case '7': xCount++;
				  yCount++;
				  zCount++;
				break;
		}
		xCount = g_pVertices[index].x;
		yCount = g_pVertices[index].y;
		zCount = g_pVertices[index].z;
		index++;
	}
}

rborob

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Mar 31st, 2005

Re: strings as input, substr and len

would something like this work?

C++ Syntax (Toggle Plain Text)
	const int MAX_ADDRESSES = g_NumberOfAdds;
	StrType word;
	ifstream fp;
	StrType words[MAX_ADDRESSES];
	int numAdds = 0;
 
	word.MakeEmpty();
	word.GetStringFile(true, ALPHA_NUM, fp);
	while(fp && numAdds < MAX_ADDRESSES)
	{
             word.CopyString(words[numAdds]);
             numAdds++;
             word.GetStringFile(true, ALPHA_NUM, fp);
             }
	const int MAX_ADDRESSES = g_NumberOfAdds;
	StrType word;
	ifstream fp;
	StrType words[MAX_ADDRESSES];
	int numAdds = 0;
	
	word.MakeEmpty();
	word.GetStringFile(true, ALPHA_NUM, fp);
	while(fp && numAdds < MAX_ADDRESSES)
	{
             word.CopyString(words[numAdds]);
             numAdds++;
             word.GetStringFile(true, ALPHA_NUM, fp);
             }

where fp is my file pointer and g_Number Of Adds is my address count from the file

rborob

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Apr 1st, 2005

Re: strings as input, substr and len

can anyone help please? ive got most of the other stuff working its just this thats the bridge in my program that i cant seem to suss out. can anyone shed some light on this for me please?

rborob

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Dec 8th, 2008

Re: strings as input, substr and len

I dont think you explained right. Maybe take more time to explain it
Did you solve this already?

namehere05

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Dec 8th, 2008

Re: strings as input, substr and len

> 1st Apr 2005
> 2 Hours Ago
Thick end of 4 years - what do you think?

Salem

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Dec 10th, 2008

Re: strings as input, substr and len

Jaja You right didnt pay attention.

namehere05

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