🚀 go-pugleaf

Hi,

I have tried a simple problem to understand pointers but found the cout
give me a wrong output in my LM7.2 of a PIII box where the version on
the Sun workstation give me the right output. So there must be sth wrong
with the LM7.2's g++ compiler.

The code is as below:
//test.cpp. compile with g++, run with a.out
#include<iostream>
 
int main(){
        int *p=new int[10];
        for (int i=0; i<10; i++){
            *(p+i)=i*2;
            cout<<"p"<<i<<" "<<*(p+i)<<" "<<(p+i)<<endl;
 
        }
        cout<<"p= "<<p<<endl
            <<"*p= "<<*p<<endl
            <<"p++= "<<p++<<endl
            <<" *p++= "<<(*p++)<<endl
            <<" p= "<<p<<endl
            <<" *p= "<<*p<<endl;
 
}

In my box the above program give me a output as:
$a.out
p0 0 0x8049b60
p1 2 0x8049b64
p2 4 0x8049b68
p3 6 0x8049b6c
p4 8 0x8049b70
p5 10 0x8049b74
p6 12 0x8049b78
p7 14 0x8049b7c
p8 16 0x8049b80
p9 18 0x8049b84
p= 0x8049b68
*p= 4
p++= 0x8049b64
 *p++= 0
 p= 0x8049b60
 *p= 0 

$

Please note that the point p's value should be 0x8049b60 instead of
0x8049b68. The later p++ in the cout actually has affected the p in the
first place. Actually, if I place extra cout after each endl, the output
is correct. To make sure, I also run the above code in a SUN workstation
also using g++ compiler. It gives me a right output as below:

$a.out
p0 0 0x43960
p1 2 0x43964
p2 4 0x43968
p3 6 0x4396c
p4 8 0x43970
p5 10 0x43974
p6 12 0x43978
p7 14 0x4397c
p8 16 0x43980
p9 18 0x43984
p= 0x43960
 *p= 0
  p++= 0x43960
  *p++= 2
 p= 0x43968
 *p= 4
$

On the sun, the g++ -v and uname -a gives a output as
$g++ -v
 Reading specs from
/opt/gcc-2.95.2/lib/gcc-lib/sparc-sun-solaris2.7/2.95.2/specsgcc version
2.95.2 19991024 (release)
$uname -a
SunOS expert.cc.purdue.edu 5.7 Generic_106541-12 sun4u sparc
SUNW,Ultra-Enterprise 
$

On my box, the g++ -v and uname -a gives me a output as:
$g++ -v
Reading specs from /usr/lib/gcc-lib/i586-mandrake-linux/2.95.3/specs
gcc version 2.95.3 19991030 (prerelease) 
$uname -v
Linux pvil-a-070.resnet.purdue.edu 2.2.17-21mdk #1 Thu Oct 5 13:16:08
CEST 2000
i686 unknown 
$

Any response welcome.