dear linux(or g++) user/programer with c++: my name is eric, when I use most
current g++ 4.3.3 on ubuntu to test 2 simple c++ programs, one have compiler
error,
--------------------
// formore.cpp -- more looping with for
#include <iostream>
using namespace std;
const int ArSize = 16; // example of external declaration
int main()
{
double factorials[ArSize];
factorials[1] = factorials[0] = 1.0;
// int i;
for (int i = 2; i < ArSize; i++)
factorials[i] = i * factorials[i-1];
for (i = 0; i < ArSize; i++)
cout << i << "! = " << factorials[i] << endl;
return 0;
}
--------------------------------------------------------
e...@eric-laptop:~/Documents/c++primerplus/download/ch05$ g++ formore.cpp
formore.cpp: In function int main():
formore.cpp:12: error: name lookup of i changed for ISO for scoping
formore.cpp:12: note: (if you use -fpermissive G++ will accept your code)
--------------------------
or even more simpler
--------
#include <iostream>
using namespace std;
int main () {
for (int i=0; i<5; i++)
cout << "C++ know loops.\n";
cout << i << endl;
return(0);
}
--------------------
e...@eric-laptop:~$ g++ try.c++
try.c++: In function int main():
try.c++:11: error: name lookup of i changed for ISO for scoping
try.c++:11: note: (if you use -fpermissive G++ will accept your code)
------------------
--------------------
the other is OK
---------------
// bigstep.cpp -- count as directed
#include <iostream>
int main()
{
using namespace std;
cout << "Enter an integer: ";
int by;
cin >> by;
cout << "Counting by " << by << "s:\n";
for (int i = 0; i < 100; i = i + by)
cout << i << endl;
return 0;
}
-----------------------
e...@eric-laptop:~/Documents/c++primerplus/download/ch05$ g++ bigstep.cpp
e...@eric-laptop:~/Documents/c++primerplus/download/ch05$ ./a.out
------------
you can see both programs, their for loop are very similar(or the same)
for (int i=0
but why first , and second programs can not compile
but
the third one is OK
?
please advice, thanks in advance your effort and time, [email protected]
