Basic For

This question must be silly though...
I myself find it very silly...
will this not work for multiple conditions
I am really puzzled at this one

Code:

---

#include<iostream>
using namespace std;
int main()
{
  int i,j;
  for(i=1;i<=5;i++)
  {
  for(j=1; j<=5 ,j>=i ;j++)
  {
    cout<<"\n"<<i<<"-"<<j;
    }
}

return 0;
}

---

will the comma in for loop not symbolise AND...
Ofcourse i used AND explicitly...
But i need to know why this is not working
---I may be wrong

The indentation is difficult to read. The comma is not equivalent to AND. Even if it was, that's a very strange condition; it looks like when i is 1 the j loop will run 5 times, if i is anything else though, the j loop will not run. I can't tell what you are trying to accomplish.

Quote:

---

Originally Posted by dpp

This question must be silly though...
I myself find it very silly...
will this not work for multiple conditions
I am really puzzled at this one

Code:

---

#include<iostream>
using namespace std;
int main()
{
  int i,j;
  for(i=1;i<=5;i++)
  {
  for(j=1; j<=5 ,j>=i ;j++)
  {
    cout<<"\n"<<i<<"-"<<j;
    }
}

return 0;
}

---

will the comma in for loop not symbolise AND...
Ofcourse i used AND explicitly...
But i need to know why this is not working
---I may be wrong

---

The comma operator is very much different than the AND. In your loop comma operator will be evaluated in left to right associativity. SO finally j>=i condition will only matter for the loop. For example if you initialize j=0 in the second for loop nothing will be printed.

That was a dummy example to know the use of comma...

All i need is:

Code:

---

for(i=1;i<=n;i++)
{
for(j=1;j<=n;j++)
{
------------------------------------------

---
--

}
}

---

The loops should only run for i<j...

1.well i know i can give an 'if' condition explicatly to check that...
But i don't need that...
I need to do the checking in the loop condition itself

So where's the problem. Just put a condition in the first for loop i<j and initialize j at the definition place itself.

what value will i initialise to 'j'...
it has to loop through in the second for loop in the next step
I dont get it clearly...
sorry :(

I did solve it using AND in the second for loop but..I need to know the optimistation without AND

I think it'll depend on whether how many times you want the loop to work. What exactly do you want to do?

Code:

---

for(i=1;i<=5;i++)
{
for(j=1;j<=5;j++)
{
if(i<j)
cout<<i<<"-"<<j;
}
}

---

I need to have the similar logic without explicit 'if' condition

So you want j to be at least one larger than i?

Code:

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for (i = 1; i <= 4; ++i) {
    for (j = i + 1; j <= 5; ++j) {
    ...
    }
}

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