Question

hello every one i want to ask that i have read that we can declare dynamic array only by using pointer and using malloc or newlike

int * array = new int[strlen(argv[2])];

but i have wrote

int array[strlen(argv[2])];

it gave me no error

i have read that static array can only be declared by giving constant array size but here i have given a variable size to static array

why is it so thanks

---

is it safe to use or is there chance that at any latter stages it will make problem i am using gcc linux

Answer 1

What you have is called a variable-length array (VLA), and it is not part of C++, although it is part of C99. Many compilers offer this feature as an extension.

Even the very new C++11 doesn’t include VLAs, as the entire concept doesn’t fit well into the advanced type system of C++11 (e.g. what is decltype(array)?), and C++ offers out-of-the box library solutions for runtime-sized arrays that are much more powerful (like std::vector).

In GCC, compiling with -std=c++98/c++03/c++0x and -pedantic will give you a warning.