Static array vs. dynamic array in C++

c++ dynamic arrays static allocation
user69514 picture user69514 · Apr 20, 2010 · Viewed 227.8k times · Source

What is the difference between a static array and a dynamic array in C++?

I have to do an assignment for my class and it says not to use static arrays, only dynamic arrays. I've looked in the book and online, but I don't seem to understand.

I thought static was created at compile time and dynamic at runtime, but I might be mistaking this with memory allocation.

Can you explain the difference between static array and dynamic array in C++?

Answer

Michael Mrozek picture Michael Mrozek · Apr 20, 2010

Local arrays are created on the stack, and have automatic storage duration -- you don't need to manually manage memory, but they get destroyed when the function they're in ends. They necessarily have a fixed size:

int foo[10];

Arrays created with operator new[] have dynamic storage duration and are stored on the heap (technically the "free store"). They can have any size, but you need to allocate and free them yourself since they're not part of the stack frame:

int* foo = new int[10];
delete[] foo;

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