Very Basic C++ question

I am new to programming in C++, just now I tried to create an array with 'n' index'es where n is an input no. This is what i coded:

Code:

#include<iostream>
using namespace std;

int main()
{
    int n=10,m;
    cin >> n >> m;
    int stor[n];
    return(0);

}

But, VC++ 6.0, returns, the following errors:

Compiling...
Cpp2.cpp
C:\Documents and Settings\Darshit Shah\C++\Euler\IOI\Cpp2.cpp(8) : error C2057: expected constant expression
C:\Documents and Settings\Darshit Shah\C++\Euler\IOI\Cpp2.cpp(8) : error C2466: cannot allocate an array of constant size 0
C:\Documents and Settings\Darshit Shah\C++\Euler\IOI\Cpp2.cpp(8) : error C2133: 'stor' : unknown size
Error executing cl.exe.

Please help... how do i create such an array??
This syntax used to work in Java

The size of an array must be known at compile-time. ie, if you had done :

Code:

int stor[10];

it would have worked, but since the size of an array is a variable, it won't work. That's why it says "expected constant expression".

To do what you intend, try :

Code:

int* stor = new int[n];

Java != C++.

Thanks a lot... Im new to C++, and all this hasnt been taught to us yet in college, just tried doing this with my existing programming knowledge, many syntax's worked though wasnt aware of this rule in C++

Code:

#include<iostream>
using namespace std;

int main()
{
    int n=10,m;
    cin >> n >> m;
    int* stor = new int[n];
    int* sums = new int[m];
    for(int i=0; i<n; i++)
    {
        int x;
        cin >> x;
        stor[i] = x;
    }
    for(int k=0; k<m; k++)
    {
        int s,e;
        cin >> s>> e;
        int sum=0;
        for(int j=(s-1); j<e; j++)
        {
            sum+=stor[j];
        }
        sums[m] = sum;
    }
    for(int l=0; l<m; l++)
    {
        cout << sums[l];
    }
    return(0);

}

Can someone please correct this code and tell me why am I not getting a output, after some checks I realised that the array sums[] does contain the perfect values that it should, but when trying to print it in the last loop, it is giving garbage values

What do you mean, garbage values? If it looks like a really big, but single number, then it would be because you're not inserting spaces between the numbers. Try :

Code:

cout << sums[l] << endl;

If that still doesn't work, simplify the program until you get an answer, and then add to it.

use the new operator for the stor.

Try int *stor new int[n];
I am sure it will work.
You need to use pointers for dynamic initialisation of an array.

@MetalheadGautham : I HAVE used pointers for the initialisation.. see the code.. yea.. initially i wasnt aware. but now I know that I must use pointers for dynamic initialisation.

@Sykora : No, it isnt one big number.. I would've realised that folly very easily!! It shows the same particular number again and again... and that value is in no way related to the program

stor[] is bounded by n. Your summing loop doesn't take care of that and thus out of bound garbage values may get added!

That, and your sums[m] = sum; line must read sums[k] since that is the counter and m is the size, which is just outside the boundary.