don't get it || operator

Code:

#include <iostream>
using namespace std;

int main ()
{
	long int x = 0;
	start:
	if (x != 128)
	{
		if (x == 9){x++;} //31 space//13 enter//10 enter//9 tab
		if (x == 10){x++;} //31 space//13 enter//10 enter//9 tab
		if (x == 13){x++;} //31 space//13 enter//10 enter//9 tab
		if (x == 32){x++;} //31 space//13 enter//10 enter//9 tab
		cout << (char)x;
		cout << x << endl;
		x++;
		goto start;

	}
	return 0;
}

this is how I like it but why I can't make code:

Code:

#include <iostream>
using namespace std;

int main ()
{
	long int x = 0;
	start:
	if (x != 128)
	{
		if (x == 9||10||13||32){x++;} //31 space//13 enter//10 enter//9 tab
		cout << (char)x;
		cout << x << endl;
		x++;
		goto start;

	}
	return 0;
}

Code:

		if (x == 9||10||13||32){x++;} //31 space//13 enter//10 enter//9 tab

this if is allways possible why?

You must be explicit, ie:
if (x == '\t' || x == '\n' || x == '\r' || x == ' ')
I also suggest that you change x's type to char, remove the cast when printing x, and remove goto in favor of a real loop.
Finally, use characters instead of magic numbers, such as the example above.

ok thanks


ok new code it's shorter yes you're right

Code:

#include <iostream>
using namespace std;

int main ()
{
	int x =0;
	char y=x;
	for (x=0;x!=128;x++&&y++)
	{
		if (x==9){x=x+2;y=x;}
		if (x==13||x==32){x++&&y++;} //32 space//13 enter//10 enter//9 tab
		cout << y << x << endl;
	}
	return 0;
}

can I make it in 1 line as 9 and 10 are together so if 9 + 2 if other numbers +1?

but another thing i don't know

Code:

		if (x==9){x=x+2;y=x;}
		if (x==13||x==32){x++&&y++;} //32 space//13 enter//10 enter//9 tab

can i make this code shorter

I think you should check out the reference for <cctype>.

In particular, whitespace is detected with isspace (and printable characters with isprint).

Code:

#include <iostream>
#include <cctype>
using namespace std;

int main ()
{
    int x =0;
    for (x=0;x!=128;x++) {
        if (!isspace(x)) {
            std::cout << char(x) << ' ' << x << '\n';
        }
    }
    return 0;
}

That's not correct usage of && there. In this piece of code:

Code:

x++&&y++

y will not increment if x is zero.
The right way to do it inside the incrementing part of the for loop is to use a comma:

Code:

x++, y++

Or elsewhere, just use a regular semi-colon.

You can also use x += 2 instead of x=x+2