The University of Iowa
The College of Liberal Arts and Sciences
Department of Computer Science
Lecture/Lab #18
new and delete, arrays, array vs vector
What do we gain by using heap memory allocation?
What do we lose by using heap memory allocation?
What are some differences between pointers and references?
What does the following statement do? What are the types of the four variables below?
auto ptr = new int( 42 );
auto i = *ptr;
auto j = &i;
auto k = &*ptr;
What's an address space?
ptr (0xff000070)
j (0xffffffe4)
k (0xff000070)
i (42)
Stack
42
Heap
0xff000070
auto ptr = new int( 42 );
auto i = *ptr;
auto j = &i;
auto k = &*ptr;
0xffffffe8
0xffffffe4
0xffffffdc
0xffffffd4
Replace question marks with "stack", "heap" or "global", according to your understanding of the language rules
Open the exercise template
Write your code, press Run to test
When you're done, grab your Repl's link and send it as a direct message to me (agurtovoy)
Click on the corresponding option in the "Lab18 exercises" poll in #general
new type
new type()
new type( value )
delete ptr
int main() {
int a[10] = { 5, -1, 0, 12,
-7, 13, 99, 64,
11, -22 };
std::cout << a[0] << std::endl;
std::cout << a[1] << std::endl;
}a[6]
Stack
a[5]
a[4]
a[3]
a[2]
a[1]
a[0]
a[7]
a[8]
a[9]
int main() {
std::vector<int> a = {
5, -1, 0, 12,
-7, 13, 99, 64,
11, -22 };
std::cout << a[0] << std::endl;
std::cout << a[1] << std::endl;
}a[6]
Heap
a[5]
a[4]
a[3]
a[2]
a[1]
a[0]
a[7]
a[8]
a[9]
a (ptr=0xff000050, size=10)
Stack
0xff000050