C++ Tutorial: static vs dynamic memory

It can be confusing to know which type of memory to use in your programs. In this video I explain the differences between static and dynamic memory, and provide an example application of dynamic memory.

static memory is allocated on the stack at compile-time. This means it is fixed in size for the duration of the program.

dynamic memory is allocated on the heap at run-time. This means the size of the memory you get is determined /after/ the program has already started running.

this benefit comes at a cost of requiring extra work. A pointer will be needed as well as two new key words, new and delete. It's up to the programmer to manage this memory in C++ and make sure there are no memory leaks.

[matx]

Regarding the 0:53, what if my program is:

int main(){
int n;
cin << n;
int array[n];
}

Here the user responsible for the size of memory

[jvsnyc]

~10:30 static allocation doesn't happen on the stack, but in a separate static data area. Local variables and function/method parameters of course ARE on the stack, those are called "automatic" but the keyword for this, 'auto' was so seldom used that they re-purposed it into the stand-in for type inference in declarations instead in 2011. A minor terminology detail, this is a good video. Both static and automatic (stack) usage can happen for anything that is a primitive, built-in type or an array of something of some size known at compile time. Actual static allocation is considered a major anti-pattern by many, when I first leaned C as a kid, we were taught never to use static allocation because it would break multi-threading, in the early 90's we were avoiding it because it broke multi-user stuff on Mainframe OS's.
Stack / automatic variable usage was of course just fine, so in a way it isn't great to use the term static to cover automatic (or simply 'stack') allocation on the stack -- it may not be loved, but it is a legitimate and real option for placing objects of known size at compile time.

[sipanmohammed]

static allocation memory must have keyword static and store in static memory, its different from automatic memory allocation which store in stack memory.