{"id":11,"date":"2026-08-17T15:30:53","date_gmt":"2026-08-17T15:30:53","guid":{"rendered":"https:\/\/corpusgame.com\/?p=11"},"modified":"2026-08-17T15:30:57","modified_gmt":"2026-08-17T15:30:57","slug":"c-basic-reference-template-allocate","status":"publish","type":"post","link":"https:\/\/corpusgame.com\/en\/c-basic-reference-template-allocate\/","title":{"rendered":"[C++ Basic] Reference, Template, Allocate"},"content":{"rendered":"

Introduction<\/h2>\n\n\n\n
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To study C++ basics, you need to understand the fundamental differences from other languages. Those differences lie in memory management, handling original variables, and dealing with addresses. Moving forward, we will learn about these concepts in C++.,<\/p>\n<\/blockquote>\n\n\n\n

C++ Basics: Difference between Static Allocation and Dynamic Allocation<\/h2>\n\n\n\n
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I will organize this because it's a very basic concept that you shouldn't not know, but it can still be confusing.<\/p>\n<\/blockquote>\n\n\n\n

Static allocation and dynamic allocation are related to compilation; if the memory size and location are determined at compile time, it is static allocation, and if they are specified during runtime, it is dynamic allocation.<\/p>\n\n\n\n

For reference, since static allocation is stored on the stack and dynamic allocation is stored on the heap, it remains in memory even after the function ends, so you must always deallocate it.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n
int main() {\n    int n;\n    cout << \"\ubc30\uc5f4 \ud06c\uae30 \uc785\ub825: \";\n    cin >> n;\n\n    \/\/ \ub3d9\uc801\uc73c\ub85c \ubc30\uc5f4 \ud560\ub2f9\n    int *arr = new int[n];\n\n    \/\/ \ubc30\uc5f4 \ucc44\uc6b0\uae30\n    for (int i = 0; i < n; i++) {\n        arr[i] = i * 10;\n    }\n\n    \/\/ \ubc30\uc5f4 \ucd9c\ub825\n    for (int i = 0; i < n; i++) {\n        cout << arr[i] << \" \";\n    }\n    cout << endl;\n\n    \/\/ \ub3d9\uc801 \ud560\ub2f9 \ud574\uc81c\n    delete[] arr;\n    \/\/ \uac12 \ud0c0\uc785\uc774\uba74 delete\n\n    return 0;\n}<\/code><\/pre>\n\n\n\n
Because it is impossible to change the size of an array at runtime, dynamic allocation must be used to receive input from the user and set the size. With static allocation, it is impossible to change the size of an array by receiving input from the user.
\u26a0\ufe0f You must free the memory using delete[] \u2013 since the memory was allocated as an array, it must be deallocated as an array.
General variables are freed with delete.<\/p>\n\n\n\n
Functions and Structures<\/h2>\n\n\n\n
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Of course I know functions and structs, but what is C++? Isn't it a language that deals with memory? That's why we could change values by using pointers as a way to pass values to functions.<\/p>\n<\/blockquote>\n\n\n\n
function parameters<\/h3>\n\n\n\n
void changeValue(int *ptr) {\n    ptr += 5;\n}\n\nint main() {\n    int num = 10;\n    std::cout << "num before change: " << num << std::endl; \/\/ 10\n\n    changeValue(&num);  \/\/ Pass the address of num\n\n    std::cout << "num after change: " << num << std::endl; \/\/ 15\n\n    return 0;\n}<\/code><\/pre>\n\n\n\n
In this way, you can pass the address of a value type and modify it as desired.<\/p>\n\n\n\n
void changeValue(ref int number) {\n    number++;\n}\nint x = 5;\nchangeValue(ref x);  \/\/ x is now 6<\/code><\/pre>\n\n\n\n
void changeValue(out int a) {\n    a = 10;\n}\nint y;\nchangeValue(out y);  \/\/ y is now 10<\/code><\/pre>\n\n\n\n
For reference, in C# as well, ref<\/code>\uc640 out<\/code> You can change the value using keywords, ref<\/code>is that initialization must be performed out<\/code>is that you don't have to do it.<\/p>\n\n\n\n
struct<\/h3>\n\n\n\n
struct Person{\n    string name;\n    int age;\n    float height;\n}<\/code><\/pre>\n\n\n\n
If you created a struct like this, you need to access it<\/p>\n\n\n\n
Person adult;\nadult.name = \"yoon\";\nadult.age = 24;<\/code><\/pre>\n\n\n\n
If it is statically allocated like this, the individual members inside the structure .<\/code>can be accessed using.<\/p>\n\n\n\n
Person *adult = new Person;\nadult -> name = \"yoon2\"\nadult -> age = 23;<\/code><\/pre>\n\n\n\n
Dynamic allocation is -><\/code>It must be accessed using.<\/p>\n\n\n\n
Person* arr = new Person[3];\narr[0].name = \"Alice\"; \/\/ Using the . operator\narr[1].age = 25;<\/code><\/pre>\n\n\n\n
For your information, when accessing array elements, both static and dynamic methods are used. .<\/code>is used.<\/p>\n\n\n\n
Constant<\/h2>\n\n\n\n
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In C#, you can create constants using `const` and `readonly`; similarly, in C++, you can create constants using `const`. (`readonly` is not supported.)
Reference variable<\/p>\n<\/blockquote>\n\n\n\n
Pointer variables and constness<\/h3>\n\n\n\n
int main() {\n    int a = 2;\n    const int *ptr = &a;\n\n    a = 1; \/\/ Compiles successfully\n    *ptr = 10; \/\/ Error\n}<\/code><\/pre>\n\n\n\n