🔵 Core C++ · Lesson 27

Dynamic Memory: new and delete

What is Dynamic Memory: new and delete?

Dynamic Memory: new and delete
Dynamic memory is allocated during program execution using new and released using delete. It is used when required size is not known at compile time.

Level
🔵 Core C++ Features

Example File
dynamic-memory.cpp

Main Focus
Concept + syntax + practical C++ program

Why should you learn this?

It helps you write correct and readable C++ programs.
It is used repeatedly in school practicals, projects and competitive programming.
It builds the base for advanced topics such as OOP, STL and data structures.

Important Terms

Term	Meaning / Use
heap	Heap used in Dynamic Memory: new and delete programming.
new	New used in Dynamic Memory: new and delete programming.
delete	Delete used in Dynamic Memory: new and delete programming.
memory leak	Memory leak used in Dynamic Memory: new and delete programming.
dynamic array	Dynamic array used in Dynamic Memory: new and delete programming.

Syntax / Pattern

int *p = new int; delete p;

Example Program

#include <iostream>
using namespace std;
int main(){
    int *p = new int;
    *p = 100;
    cout << *p;
    delete p;
    return 0;
}

Expected Output

100

Program Explanation

new allocates memory from heap.
delete releases allocated memory.

Exam Tip: In C++ practical answers, write the logic first, then the program, then expected output. For theory, always include one suitable example.

Where will you use it?

dynamic arrays
linked lists
runtime object creation

Common Mistakes

Forgetting delete.
Using pointer after delete.
Mixing new/delete with malloc/free.

Practice Tasks

Create dynamic array of n marks.
Explain memory leak with example.

Summary

Dynamic Memory: new and delete is an important C++ topic. Learn the definition, understand the syntax, run the example program and then solve the practice tasks to make the concept strong.