From the bottom of my heart, thank you SO MUCH for this. I have been having the hardest time understanding pointers because no resource I had found was hitting quite the right spot on why we should care about pointers, but you did it. Thank you for taking the time to demonstrate the memory allocation and your attention to discussing that side of things. I have been pulling my hair out over this, and I cannot tell you how overjoyed I am to have found this video.
Ive been learning C++ as a 1st year CS student from around 5 months now and Im currently dealing with pointers from my book resources. I was very confused about the concept of new and delete operators and was wondering why I should use them and now Im starting to understand their functions and how important they are on memory management, thank you so much!
7:14 int *ptr_to_int = new int(5); // to store an integar. double *array = new double[5]; //to store an array. So, round brackets ( ) to allocate single value and square brackets [ ] to allocate an array with the new operator. So, the basic syntax for the new operator is: datatype *var_name = new datatype(); or datatype *var_name = new datatype(val); //when we pass a value (might be an int or string or any other data type)
Thank for this tutorial. But I couldn’t find out a tutorial of yours on placement new. Please can we have a tutorial on that whenever you have time. Thank you once again.
great video! at 6:47, you have declared a pointer that stores the adress of the first element of an array, right? so, when assigning the values to the array, why couldn't we say, for example, *array[0] = 5?
Great question! 🙂You can use pointer notation with arrays but it looks a bit different than that, this video gets into that topic: ua-cam.com/video/hWGYBMO553A/v-deo.html.
Let's say you have a 2D pointer array of objects and the pieces in the array is dynamically allocated. Why would it be a terrible idea to "delete" a specific entry, arr[i][j] and attempt to assign nullptr afterwards to that entry? I attempted that with a specific piece of code in my chess game in the one case it caused a segfault and the other case it functioned seemingly fine. I am new to C++ so this is a bit confusing.
truly appreciate your video ! Btw, can you link the document related to constructor syntax (name(name) {}) in 11:34 please ? I havent seen it before. Thank you.
That's called a member initializer list, this video covers the concept: ua-cam.com/video/X1dGUSVnavQ/v-deo.html. There is some more 'official documentation' here: en.cppreference.com/w/cpp/language/constructor. 🙂
Would it not be better to declare the big_array pointer out of the try-block and initialize it with a nullptr? After the allocation happens and the main terminates, this is going to result in a memory leak.
That example was to demonstrate memory allocation failure, so no memory was going to be allocated. If no memory is allocated, we don't need to delete/free the allocated memory. Also, when the main function terminates all memory is going to be "released". When the program stops executing there are no more memory leaks.
s1 will have y be a pointer to variable x. In other words, y will store the memory address that the variable x is located at. x is located in a place in memory called the stack. s2 uses dynamic memory allocation with the new operator. The new operator will create space to store a new int value, in a place in memory called the heap. That new int value will be set to whatever value x is set to, in this case 5. This new int value will have no relationship to x though. The value of x is used to set this new int value, that's all. And y will store the memory address of this new int value on the heap.
@@PortfolioCourses I see. Btw, could you cover Maps in the short term? Idk if they are on your planed videos (I guess), but it would be a very interesting topic along with unique_ptrs and stuff. Good Video again Kevin!. Keep up with the good content!
Please do NOT use new/delete to dynamically allocate/deallocate memory in production code. Use smart pointers (std::unique_ptr, std::shared_ptr with the helper functions std::make_unique and std::make_shared) instead. By the way, avoid using namespace std; and use nullptr instead of NULL.
(If im not wrong) we need to make this a pointer to point to the address of the int, it's like if we were making int* ptr = &var but instead of using a already initialized variable we create one with the new keyword, the pointer just points to the address of the new dynamically allocated variable, after we finish we need to use delete because if we dont do it we'll cause a memory leak.
The clarity of this video is beyond incredible. Fantastic work!
I'm glad you enjoyed it! :-)
yes how did you manage that
My God, if I had just watched this 15 minute video before starting my project it would eliminate like 2 hours of confusion...
From the bottom of my heart, thank you SO MUCH for this. I have been having the hardest time understanding pointers because no resource I had found was hitting quite the right spot on why we should care about pointers, but you did it.
Thank you for taking the time to demonstrate the memory allocation and your attention to discussing that side of things. I have been pulling my hair out over this, and I cannot tell you how overjoyed I am to have found this video.
I love the commented diagram you made below the code. Really helped a bunch of stuff click.
I'm glad you enjoyed it! 🙂
your courses on C and C++ are the best on the internet. You explain everything perfectly. Thank you very much. Keep up!
Ive been learning C++ as a 1st year CS student from around 5 months now and Im currently dealing with pointers from my book resources. I was very confused about the concept of new and delete operators and was wondering why I should use them and now Im starting to understand their functions and how important they are on memory management, thank you so much!
You’re very welcome I’m glad the video was helpful for you to learn these ideas! :-)
are you an angel? ive been trying to understand this for days and you're the only one that made it make sense
I'm so glad to hear this video was able to help you out! :-)
7:14
int *ptr_to_int = new int(5); // to store an integar.
double *array = new double[5]; //to store an array.
So, round brackets ( ) to allocate single value and square brackets [ ] to allocate an array with the new operator.
So, the basic syntax for the new operator is:
datatype *var_name = new datatype();
or
datatype *var_name = new datatype(val); //when we pass a value (might be an int or string or any other data type)
great playlist , you are a hidden gem!
Thank you Muhammad! 😀
oh shit this tutorial is so good -_- u deserve millions of subscribers
Thank you for the positive feedback Đức! :-)
best explanation about dynamic mem allocation
Thank you for the positive feedback Bozian, I’m glad you enjoyed it! :-)
amazing work, thank you
Thank for this tutorial. But I couldn’t find out a tutorial of yours on placement new. Please can we have a tutorial on that whenever you have time. Thank you once again.
great video! at 6:47, you have declared a pointer that stores the adress of the first element of an array, right?
so, when assigning the values to the array, why couldn't we say, for example, *array[0] = 5?
Great question! 🙂You can use pointer notation with arrays but it looks a bit different than that, this video gets into that topic: ua-cam.com/video/hWGYBMO553A/v-deo.html.
@@PortfolioCourses this has been bugging me for a while 😅, I'll definitely watch it! thank you!
You're welcome! :-D
Let's say you have a 2D pointer array of objects and the pieces in the array is dynamically allocated. Why would it be a terrible idea to "delete" a specific entry, arr[i][j] and attempt to assign nullptr afterwards to that entry? I attempted that with a specific piece of code in my chess game in the one case it caused a segfault and the other case it functioned seemingly fine. I am new to C++ so this is a bit confusing.
Thanks for making video!
If base adress is 0x0001,
ptr_to_ have to be allocated 0x0001+ sizeof(int)?
truly appreciate your video ! Btw, can you link the document related to constructor syntax (name(name) {}) in 11:34 please ? I havent seen it before. Thank you.
That's called a member initializer list, this video covers the concept: ua-cam.com/video/X1dGUSVnavQ/v-deo.html. There is some more 'official documentation' here: en.cppreference.com/w/cpp/language/constructor. 🙂
Just out of curiosity, what is the font used for coding in this video? It looks quite pleasant to me.
amazing video !
I'm glad you enjoyed it! :-)
Fantastic
Hey man, thanks for making c++ playlist, Which IDE are you using ?
You’re welcome Yusuf! I am using Xcode on a Mac in most videos, though sometimes I use Visual Studio Code and the terminal/compiler instead.
Would it not be better to declare the big_array pointer out of the try-block and initialize it with a nullptr? After the allocation happens and the main terminates, this is going to result in a memory leak.
That example was to demonstrate memory allocation failure, so no memory was going to be allocated. If no memory is allocated, we don't need to delete/free the allocated memory. Also, when the main function terminates all memory is going to be "released". When the program stops executing there are no more memory leaks.
Thanks!
You’re very welcome! :-)
i don't believe in god, but definitely you are one such!
int x = 5;
int *y = &x; //s1
int *y = new int(x); //s2
Sir, what is difference between s1 and s2 ?
s1 will have y be a pointer to variable x. In other words, y will store the memory address that the variable x is located at. x is located in a place in memory called the stack.
s2 uses dynamic memory allocation with the new operator. The new operator will create space to store a new int value, in a place in memory called the heap. That new int value will be set to whatever value x is set to, in this case 5. This new int value will have no relationship to x though. The value of x is used to set this new int value, that's all. And y will store the memory address of this new int value on the heap.
@@PortfolioCourses Thank you sir for clarification.
@@korngsamnang You're welcome! 😀
didnt you cover this topic in previous videos?
Nope, I’ve used them in previous videos but haven’t been able to cover them yet. I’ve been hoping to cover them for awhile now.
@@PortfolioCourses I see. Btw, could you cover Maps in the short term? Idk if they are on your planed videos (I guess), but it would be a very interesting topic along with unique_ptrs and stuff.
Good Video again Kevin!. Keep up with the good content!
I’m not sure when I’ll cover Maps but hopefully one day I’ll get to it all. :-)
What is the editor name?
In this video I am using Xcode on a Mac. :-)
great
I’m glad you enjoyed it! :-)
Please do NOT use new/delete to dynamically allocate/deallocate memory in production code. Use smart pointers (std::unique_ptr, std::shared_ptr with the helper functions std::make_unique and std::make_shared) instead. By the way, avoid using namespace std; and use nullptr instead of NULL.
im too dum to understand any of this
(If im not wrong) we need to make this a pointer to point to the address of the int, it's like if we were making int* ptr = &var but instead of using a already initialized variable we create one with the new keyword, the pointer just points to the address of the new dynamically allocated variable, after we finish we need to use delete because if we dont do it we'll cause a memory leak.