Why this dosen't work in C

Following code can't be compiled as a C program & but when compiled as C++ program it works.

I am experienced with C but quite to new to C++ & OOP, so please explain if you have some time.

int *SomeArray=NULL,n;
printf("Enter the number of elements in array : ");
scanf("%d",&n);
SomeArray = new int(n);

new is a c++ keyword.

EDIT:
Also... don't do this:

int *SomeArray=NULL,n;

do this:

int *SomeArray=NULL;
int n;

Anyone reading your code will thank you later on. And you will thank yourself too.

Yer, in C you gotta replace new with something like malloc() for dynamic memory.

>> int *SomeArray=NULL,n;

>> int *SomeArray=NULL;
>> int n;

I can see why Mario suggested you put it on different lines, but there isn't really a need. It's more for the sake of readability than anything. It's just that the pointer (*) indicator of SomeArray doesn't carry through to n, as I think you know. So, to distinguish between pointers, and non-pointers easily, new lines are often used.



EDIT ::

A more C++-ish implementation of your code Not color coded unfortunately

Code:

---

#include <iostream>

using namespace std;

int main( void )
{
    int *SomeArray = NULL;
    int n = 0;

    cout<< "Enter the number of elements in the array: ";
    cin >> n

    SomeArray = new int[n];

    // Do stuff with the array

    delete []SomeArray;

    return 0;
}

---

Thank You, for giving C++ code.

I tried to do following & compiled as C program but I am getting errors

code> SomeArray = realloc(SomeArray,n);
error> invalid conversion from `void*' to `int*'

I get similar error if I do it using malloc

(I use DevC++ IDE which uses gcc compiler)

I googled but, everything I find is giving some errors, Anyone knows how to do it in C, or may be I should post it in C board ?

You're using a C++ compiler to compile C code. Save the file as a .c file. If that still doesn't work, you may have to cast the *alloc call. BTW, realloc doesn't do what you want. Try malloc().

Code:

---

SomeArray = malloc(sizeof(int) * n);

---

I tried

Code:

---

SomeArray = malloc(sizeof(int) * n);

---

but it's giving same error as above. When it's saved with .c extension.

SomeArray has to be a pointer, not an array.

Try including <stdlib.h>.

Are you sure it's the same error, and not int to int* ?
Did you include stdlib.h ?

>but it's giving same error as above. When it's saved with .c extension.
If you're getting the same pointer conversion error then you're still compiling as C++. C allows conversions to and from void*, but C++ requires a cast when converting from void*.