Please help me im getting error as, 'illegal structure operation' ,I'm not able to re

[Prathibha v]

#include<iostream.h>
#include<conio.h>
#include<iomanip.h>
class sorting
{
private:int n,m[100];
public:  void getdata();
         void sort();
         void display();
};
void sorting::getdata()
{
 cout<<"how many elements?";
 cin>>n;
 cout<<"enter the elements";
       for(int i=0;i<n;i++)
           cin<<m[i];
}
void sorting::sort()
{
 int temp,j;
 for(int i=0;i<n;i++)
    {
        j=i;
           while(j>=i)
        {

.
.
.
.the error is in line 18

[dev7060]

More details from the OP are required on the environment and code for the other party to reproduce the same error. On compiling the code with TDM-GCC 4.9.2, it shows error: no match for ‘operator<<’. It's because the compiler couldn't find a matching overload for operator<<. This can be solved by the following:

...
for(int i=0;i<n;i++)
cin>>m[i];
}
...
 

[SioSio]

Differences between standard (ansi) C++ and C (ansi) code.

1.include
<C>

#include<stdio.h>
#include<conio.h>
#include<iomanip.h>
 

<c++>

#include<iostream>
#include<conio>
#include<iomanip>
 

2.standard I/O
<c>

#include <stdio.h>
int main()
{
    int n;
    printf("how many elements?\n");
    scanf( "%d", &n );
    printf("enter the elements?\n");
    :
    :
}
 

<c++>

#include <iostream>
using namespace std;
int main()
{
    int n;
    cout << how many elements?";
    cin >> n;
    cout << "enter the elements";
    :
    :
}
 

[dev7060]

It may have nothing to do with the error,
This coding looks like a mix of C and C++.

This code is written purely in C++ and is targeting the pre-standard version of C++. The OP is most probably using an ancient compiler like Turbo C++.

[SioSio]

When I examined about <iostream.h>,
-<iostream> and <iostream.h> are different headers.
-It seems that it was abolished in 2006 (or rather, <iostream.h> has never been a part of the standard since the C ++ international standard was enacted in 1998).
-Only char is supported.

The code below uses <iostream> instead of <iostream.h> and adds "using namespace std;" after the #include statement.
And Use Microsoft Visual C ++ 2017, compilation passed.

#include "pch.h"
#include <iostream>
#include<conio.h>
#include<iomanip>
 
using namespace std;
class sorting
{
private:int n, m[100];
public: void getdata();
        void sort();
        void display();
};
void sorting::getdata()
{
    cout << "how many elements?";
    cin >> n;
    cout << "enter the elements";
    for (int i = 0;i < n;i++)
    cin >> m[i];
}
void sorting::sort()
{
    int temp, j;
    for (int i = 0;i < n;i++)
    {
        j = i;
        while (j >= i)
        {
:
:
 

Line 17 ("cin >> n;" has been modified to "cin << n;") with the following source,
(Error is "Visual studio: E0349 no operator << matches these operands (but no strings in code)"

Your compilation environment seems very different from mine, so it is unclear if you can use this modified code.

[dev7060]

I have pretty much said everything that's required. There is nothing such as a mix of C and C++. A source code file can only be written in one single language with the unique file extension.

Use Microsoft Visual C ++ 2017, compilation passed.

You have made changes to the code by making it compatible to the modern compiler (removing .h from iostream.h, adding using namespace std;, etc.) Using Turbo C++, compilation can be done without even making any change to the code.

Before C++ was standardized, the I/O library was developed as <iostream.h>. Some older compiler continued to distribute the <iostream> header as <iostream.h>. Turbo C++ doesn't support namespaces. Its standard library puts the names in the global namespace. The code by the OP is not a mix of C and C++. The code is purely in C++ targeting the pre-standard version.

You might need to have a look at official docs that reveal the obsolete C++ programming.

[SioSio]

Hi dev7060.
Thank you for the information.

But,
As mentioned earlier, I have found that <iostream.h> only supports "char".
This could not be confirmed in my compile environment as <iostream.h> is not supported.


https://bytes.com/topic/c/answers/61...eam-h-iostream

Why doesn’t iostream have a .h extension?
https://www.learncpp.com/cpp-tutoria...omment-page-1/

[dev7060]

Here's some sample code from the manual of C++ Builder. Differences can be seen like the name of namespace is not mentioned, iostream.h instead of iostream etc.

#include <sysutils.hpp>
#include <iostream.h>
// non-VCL style classes
class MyBase {
public:
MyBase() { what_am_I(); }
virtual void what_am_I() { cout << "I am a base" << endl; }
};
class MyDerived : public MyBase {
public:
virtual void what_am_I() { cout << "I am a derived" << endl; }
};
// VCL style classes
class MyVCLBase : public TObject {
public:
__fastcall MyVCLBase() { what_am_I(); }
virtual void __fastcall what_am_I() { cout << "I am a base" << endl; }
};
class MyVCLDerived : public MyVCLBase {
public:
virtual void __fastcall what_am_I() { cout << "I am a derived" << endl; }
};
int main(void)
{
MyDerived d;// instantiation of the C++ class
MyVCLDerived *pvd = new MyVCLDerived;// instantiation of the VCL style class
return 0;
}
 

Source: C++ Builder 6 official manual: http://docs.embarcadero.com/products...rsGuide_EN.pdf

Why doesn’t iostream have a .h extension?

Previous replies to this thread and/or own research can answer this question.