Posts by gerard4143 - Page 19

gerard4143 371 Nearly a Posting Maven

14 Years Ago

Re: 2 Questions

And what's the problem?

Software Development c++

gerard4143 371 Nearly a Posting Maven

14 Years Ago

Re: c++ class needs to use another class

You should get into the habit of initializing data member like so

Vector::Vector ()
:x = 0,y = 0,z = 0 
{}

Vector::Vector (float a, float b, float c) 
:x = a,y = b,z = c
{}

In some situations its more efficient.

Software Development c c# c++ oop

gerard4143 371 Nearly a Posting Maven

14 Years Ago

Re: 2 Ways to write the same thing

Its very common to reassign pointers... So your line 14 is valid.

Software Development c++

gerard4143 371 Nearly a Posting Maven

14 Years Ago

Re: Switch statement and call to a member function

Hi guys again,
I have tried the code and it doesnt seem to work.
In the other hand I have manipulate the code so that I have a function to display all customers and this is working!!!
:(

What code? You'll have to post it if you want us to look at it.

Software Development c++

gerard4143 371 Nearly a Posting Maven

14 Years Ago

Re: 2 Ways to write the same thing

Try looking at the attached code...It may help straighten things out or it just might confuse you more..

#include <stdio.h>
#include <stdlib.h>

int main()
{
	int i = 0;
	int *iptr = (int*)malloc(sizeof(int) * 10);
	int **tptr;

	for (i = 0; i < 10; ++i)
		*(iptr + i) = i;

	for (i = 0; i < 10; ++i)
		fprintf(stdout, "ans->%d\n", *(iptr + i));

	tptr = &iptr;

	for (i = 0; i < 10; ++i)
		fprintf(stdout, "ans->%d\n", *(*tptr + i));
	
	return 0;
}

I really should have used C++, so here look at this one

#include <iostream>

int main()
{
	int i = 0;
	int *iptr = new int[10];
	int **tptr;

	for (i = 0; i < 10; ++i)
		*(iptr + i) = i;

	for (i = 0; i < 10; ++i)
		std::cout << "ans->" << *(iptr + i) << std::endl;

	tptr = &iptr;

	for (i = 0; i < 10; ++i)
		std::cout << "ans->" << *(*tptr + i) << std::endl;
	
	delete [] iptr;
	
	return 0;
}

Software Development c++

gerard4143 371 Nearly a Posting Maven

14 Years Ago

Re: 2 Ways to write the same thing

Its the same for both examples.

Software Development c++

gerard4143 371 Nearly a Posting Maven

14 Years Ago

Re: Switch statement and call to a member function

Your going about this the wrong way. Customers member function 'showCustomers' shouldn't loop through the Customers objects, it should only display its values.

You should have a loop like

for (int i = 0; i < 150; ++i)
{
CustArray[i].showCustomers();
}

Software Development c++

gerard4143 371 Nearly a Posting Maven

14 Years Ago

Re: 2 Questions

Your Hi variable

char Hi[4] = {'3','E','2','C'};

is four bytes with the values of(in ascii)
0x33 = '3'
0x45 = 'E'
0x32 = '2'
0x43 = 'C'

and this (in ascii)

Bye[0] = 0x3E and Bye[1] = 0x2C

would equate to

Bye[0] = '>' and Bye[1] = ','

I think your mixing up characters and their acsii values.

Software Development c++

gerard4143 371 Nearly a Posting Maven

14 Years Ago

Re: convert double to string problem

Try working with setprecision like below

#include<iostream>
#include <iomanip>


int main()
{
	double my_f = 1.0/3.0 / 30.0;
	std::cout << my_f << std::endl;
	std::cout << std::setprecision (100) << my_f << std::endl;


}

Software Development c++

gerard4143 371 Nearly a Posting Maven

14 Years Ago

Re: pointers c++

The memory manager is choking on your pointer 'p' because you incremented its value.

Check the enclosed code..

#include<iostream>
using namespace std;

int main()
{
  int* p=new int[2];
  p[0]=1;
  p[1]=2;
  cout<<p[0]<<" "<<&p[0]<<endl;
  cout<<p[1]<<" "<<&p[1]<<endl;
  cout<<endl;
  cout<<*p<<" "<<p<<endl;
  p++;
  cout<<*p<<" "<<p<<endl;
  p--;//set pointer back to its original value
  delete [] p;
}

Software Development c++

gerard4143 371 Nearly a Posting Maven

14 Years Ago

Re: pointers c++

If your going to increment your pointer then save its original value somewhere and delete that.

Software Development c++

gerard4143 371 Nearly a Posting Maven

14 Years Ago

Re: copying contents of a text file to another text file

Line 19...Why are you closing write here?

actually line 16...Why are you opening write here?

Try looking at the code below

#include <stdio.h>
#include <stdlib.h>

#define BSIZE 24

int main()
{
	char ch[BSIZE];
	FILE *fout;
	FILE *fin;

	if (!(fin = fopen("testfile", "r")))
	{
		fputs("could not open testfile!\n", stderr);
		exit(EXIT_FAILURE);
	}

	if (!(fout = fopen("testout", "w")))
	{
		fputs("could not open testout!\n", stderr);
		exit(EXIT_FAILURE);
	}

	while (fwrite(ch, sizeof(char), fread(ch, sizeof(char), BSIZE, fin), fout))
	{
	}

	fclose(fout);
	fclose(fin);
	return 0;
}

Software Development c file-system

gerard4143 371 Nearly a Posting Maven

14 Years Ago

Re: problem with structures.

This code has some things that you should avoid like

fflush(stdin);

This is a no no.

Plus this

PATIENT_DATA section_1[40]= {"","","","",0,"","","","",0};

I'm not sure what the effect is here...Does it initialize the first element? I'm not really sure, one of the C language lawyers will have to comment on this one..

Here's a cleaned up version of the posted code

#include <stdio.h>

typedef struct
{
	char first_name[20];
	char middle_name[20];
	char last_name[20];
	char illness_type[5];
	int patient_number;
	char doctor_fname[20];
	char doctor_lname[20];
	char emer_fname[20];
	char emer_lname[20];
	int emer_telephone;
} PATIENT_DATA;

int main()
{ 

	PATIENT_DATA section_1 = {"","","","",0,"","","","",0};
	printf("\nPatient First Name: ");

	fgets(section_1.first_name, sizeof(section_1.first_name), stdin);

	return 0;
}

Please note, if you post code use the code tags.