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In C++, both ptr++ and ++ptr are used to increment pointers, but they behave differently in expressions. The difference lies in when the increment happens: before or after the value is used. This is essential when working with loops, arrays, or pointer. Syntax Following is the syntax to compare ptr++ vs ++ptr in C++: ptr++: post-increment; ++ptr: pre-increment; Following is the table to compare ptr++ vs ++ptr in C++ ... Read More
In C++, direct memory access is possible using pointers. However, the improper use of pointers can lead to problems such as dangling pointers, null pointers, void pointers, and wild pointers. You must have to fix these problems properly for correct code compilation and execution. Let us learn how these problems occur and how you can fix them. Dangling Pointer A dangling pointer is a variable that points to invalid or freed memory, causing errors if accessed. It is like calling a disconnected phone number. When the local variable is not static, the pointer pointing to it becomes dangling. Syntax Following ... Read More
The (int)x is C-style typecasting, where static_cast(x) is used in C++. This static_cast() gives a compile-time checking facility, but the C-style casting does not support that. This static_cast() can be spotted anywhere inside a C++ code. And using this C++ cast, the intentions are conveyed much better. In C like cast, sometimes we can cast some type pointer to a point some other type data. Like one integer pointer can also point character type data, as they are quite similar, the only difference is character has 1-byte, integer has 4-bytes. In C++, the static_cast() is more strict than C-like casting. ... Read More
To find the Current Working Directory (CWD) in C or C++ is like asking your program: "Hey, where am I right now?". Simply we can say that it is like a folder of your program which is present and used to operate in. We can use functions like getcwd() from unistd.h in C/C++ or filesystem::current_path() from C++17. Below are the list of the ways to achieve this. Using getcwd() in C/C++ Using filesystem in C++17 Using getcwd() Function in C/C++ In C/C++, we use the getcwd() function. This function gets ... Read More
The C++ interfaces are implemented using abstract classes and these abstract classes should not be confused with data abstraction which is a concept of keeping implementation details separate from associated data. A class is made abstract by declaring at least one of its functions as a pure virtual function. A pure virtual function is specified by placing "= 0" in its declaration as follows : class Box { public: // pure virtual function virtual double getVolume() = 0; private: ... Read More
In C/C++, every character including 'a' is stored using a specific size in memory. Most of the systems including Linux, the size of a character is 1 byte. This means that any character (like a) can occupy 1 byte(8 bits of memory). To determine how much memory is used by the character 'a', we can use the sizeof() operator. So, it returns the size in bytes of a variable or data type. Following are the list of different ways to check the Standard Size in C/C++. Using sizeof with character literal ... Read More
In Python, it is often necessary to execute another file. This is common in cases such as running helper scripts, triggering workflows, or executing test cases. Python provides several ways to execute one file using another. Depending on the requirement, whether we want to reuse functions, execute a file directly, or run it as a subprocess. Let us look at these solutions one by one - Understanding Python Script Execution Before proceeding with how to run one Python file from another, it's important to understand how Python scripts are executed. When we run a Python file using python myscript.py ... Read More
In Python, the underscore (_) is a special character with different meanings based on how and where it is used. It plays a significant role in readability, naming conventions, and interpreter behavior. In this article, we will discuss different scenarios of using the Underscore(_) in Python. Single Underscore _ in Python The single underscore (_) is used in Python for special purposes, which depend on the context. These are one of the most versatile and commonly seen symbols in clean and Pythonic code. Use Cases of _ (Single Underscore) The single underscore(_) can be used in different use cases. Let's ... Read More
Among several file-handling operations in Python, the need to list all files in a directory is the most common one, and it's quite straightforward. Python offers a module named os that provides functions to work with the operating system, the directories, and the files seamlessly. In this article, we will cover ways of listing all files in a directory. The following are the different methods used to list all files in a dictionary using Python - os.listdir(): list all files in a directory os.walk(): Recursively lists all files in subdirectories ... Read More
The Heap Sort is a comparison-based sorting algorithm that sorts the numbers using a binary heap. It is an in-place sorting method, that means it sorts the array without needing any extra space. In this article, we have been given an unsorted array and our task is to implement the heap sort in C++. What is Heap Sort? The heap sort is an efficient sorting technique that first constructs the heap ADT and then removes the root element to swap it with the node having minimum value at the leaf position. Then we use the heapify method ... Read More