Why it is printing the value 578 again in line 8 even after deallocation?

Question

#include <iostream>
int main()
{
int *a=new int;
*a=578;
std::cout<<*a<<std::endl;
delete a;
std::cout<<*a;
return 5;
}

Answer 1

Yes Ujjawal Gupta

Answer 2

delete just marks the address of the resource as available again so that it can be reused.
You cannot rely on what the value might be after it, because using a deleted value is undefined behaviour.

Answer 3

Ujjawal Gupta I'm not getting the same thing with your code so I'm confused

https://code.sololearn.com/czL2iyA1Rx7a/?ref=app

Answer 4

Ujjawal Gupta but you do see that here you are getting the correct answer - true ?!

Answer 5

BroFar am using clang version 9.0.1 to compile c++17 and getting 578 two times

Answer 6

Here you are using g++ 10 Ubuntu Ujjawal Gupta on vs code editor.

https://code.visualstudio.com/docs/cpp/config-linux

Answer 7

BroFar yes sir, but why it's different in other compilers?

Answer 8

BroFar does deallocation takes place only in GCC compilers?

Answer 9

Dennis I gotcha 👍