I am Lao Wen, an embedded engineer who loves learning.Follow me to become even better together! 1 – Principles Low coupling means that modules should exist as independently as possible. While some connection between modules is inevitable, the interfaces between them should be minimal and simple. Thus, high cohesion from the internal characteristics of each … Read more
Hello everyone, welcome to <span>LiXin Embedded</span>. In embedded development, structures are an indispensable tool. Compared to classes in object-oriented programming, C language structures are more like pure data collections without methods, making them simple and efficient. For embedded engineers, it is essential to not only use structures conveniently but also to understand their layout in … Read more
In the C language, <span>extern</span>, <span>volatile</span>, and <span>inline</span> are three widely used keywords, each related to cross-file variable declarations, compiler optimization control, and function inlining. Mastering their usage can effectively enhance code structure, stability, and performance. 1. extern (External Variable Declaration) <span>extern</span> is used to declare global variables or functions defined in other files, enabling … Read more
1. Problem: How many distinct three-digit numbers can be formed using the digits 1, 2, 3, and 4 without repetition? What are they? Program Analysis: The digits that can fill the hundreds, tens, and units places are 1, 2, 3, and 4. Generate all permutations and then remove those that do not meet the criteria. … Read more
5.Why Create the Array Data Structure From the previous analysis, we can understand that the essence of an array name is a pointer. Since we already have the pointer data type, why create the array data type? Isn’t that redundant? Can we program normally without creating arrays? The answer is: Yes, it is indeed possible … Read more
Using the malloc Function for Dynamic Memory Allocation in C In C programming, memory management is an important topic, especially when dealing with memory that needs to be dynamically allocated. Dynamic memory allocation allows programs to request a specific amount of memory as needed, without having to declare the size of variables in advance. This … Read more
Content Source: Sun Wukong Seeking Knowledge Basic Terminology of State Machines Current State: Refers to the state currently being occupied. Condition: Also known as “event”, when a condition is met, it will trigger an action or execute a state transition. Action: The action executed after the condition is met. After the action is completed, it … Read more
1. Writing the C program ch03_05_01.c /* * This program constructs a structure TestStruct with members of different lengths. * It sums the structure members using both C functions and assembly functions to verify the correctness of the assembly code. * The focus is on the Pad8 member, which does not participate in calculations, but … Read more
📌 Problem Description Write a function str_replace that replaces the first occurrence of an old substring with a new substring in the given string, returning the modified new string. Requirements: Only a single replacement is required The returned new string must be dynamically allocated Example: Input: str="Hello World", old="World", new="C" Output: "Hello C" Difficulty: ⭐️ … Read more
Understanding the if Statement: A Deep Dive into C Language Control Structures In programming, control flow refers to a series of statements that determine the order of execution of a program. The <span>if</span> statement is one of the most fundamental and commonly used control structures in C language. It allows us to execute different blocks … Read more