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+---- Thread: For loop problem (/showthread.php?tid=3646)
For loop problem - GeneralOJB - 12-15-2009
Hey
Why doesn't this work:
PHP Code:
#include <iostream.h>
int main() {
int x = 0;
int i;
for (i = 1; i <= 100; i++) {
x += i;
}
cout << x << endl;
return 0;
}
For 'x', I should be getting the same as 'i' (1 going down to 100) but I get 5050.
Does anyone know what the problem is?
P.S - I'm learning from a book, so any mistakes are Jeff Cogswell's fault.
RE: For loop problem - Gaijin - 12-15-2009
Code:
x += i;Simply means x = x + i
That means your adding the "i" number to the "x" number.
Try removing the +
RE: For loop problem - GeneralOJB - 12-15-2009
This time I get '100'
Instead of
1
2
3
4
ect.
RE: For loop problem - Gaijin - 12-15-2009
Yes that is because you're declaring the x variable every time new.
To do what you want you'll need an array.
Code:
char[] x;
//then in the loop
x[i] = i;RE: For loop problem - GeneralOJB - 12-15-2009
(12-15-2009, 02:38 PM)Master of The Universe Wrote: Yes that is because you're declaring the x variable every time new.
To do what you want you'll need an array.
Code:char[] x;
//then in the loop
x[i] = i;
I'm getting an error on the 'char[] x;', it says it expected primary expression before char.
Where exactley do I put this?
And sorry im pretty new to C++.
RE: For loop problem - Brainless Control - 12-15-2009
Is that book outdated? cause new compilers also accept <iostream> as an header.
<iostream.h> is old school
RE: For loop problem - GeneralOJB - 12-15-2009
Yeah, i'm using <iostream>, the original post was copied from the old book. But I do have a new compiler. It's just the book that's old.
2003. LOL
RE: For loop problem - Brainless Control - 12-15-2009
2003...lol you might want to change the book you're reading to something up to date
RE: For loop problem - Gaijin - 12-15-2009
(12-15-2009, 02:48 PM)GeneralOJB Wrote: I'm getting an error on the 'char[] x;', it says it expected primary expression before char.
Where exactley do I put this?
And sorry im pretty new to C++.
I'm the one who need to apologize.
I was with my tought in a bit different language!
Here Take a look at this code.
Code:
#include <iostream>
using namespace std;
int main(int argc, char argv[]) {
int i = 0;
int x[101];
cout << "i:" << endl;
for(i; i <= 100; i++) {
cout << "i = " << i << endl;
x[i] = i;
}
cout << "x:" << endl;
cin.get();
for(i = 0; i <= 100; i++) {
cout << "x[" << i << "] = " << x[i] << endl;
}
cin.get();
return 1;
}RE: For loop problem - GeneralOJB - 12-17-2009
Love you <33