Siemens General + TIA Portal + EPLAN Electrical Drawing Video Recordings for Sale at Low Prices! ChuangKong Education Siemens General Class Course Introduction We know that there are various storage areas in PLCs for different purposes, such as Physical I/O Area P, Image Input Area I, Image Output Area Q, Bit Storage Area M, Timer … Read more
They look similar, but there are some differences between them. A reference is a variable that is another name for an existing variable, while a pointer is a variable that stores the memory address of another variable. What Is a Reference? A reference is a variable that is another name for an existing variable. A … Read more
Constant Pointers In C language, a constant pointer refers to a pointer whose address cannot be changed, meaning the address will remain unchanged. Therefore, we can say that if a constant pointer points to a certain variable, it cannot point to other variables. Syntax of Constant Pointers <pointer type> * const <pointer name>; The declaration … Read more
So far, we have learned that pointers should point to addresses of the same type specified in their declaration. For example, if we declare an int pointer, then this int pointer cannot point to a float variable or other types of variables; it can only point to int type variables. To solve this problem, we … Read more
1. A pipeline achieves maximum efficiency only when it is filled with instructions, meaning that one instruction is executed per clock cycle (this refers only to single-cycle instructions).If a jump occurs in the program, the pipeline will be cleared, and it will take several clock cycles to refill the pipeline. Therefore, minimizing the use of … Read more
Follow and star our public account for direct access to exciting content Source: https://www.cnblogs.com/clover-toeic/p/3730362.html Author: clover_toeic Data overwhelms everything. If the correct data structure is chosen and everything is organized neatly, the correct algorithm becomes self-evident. The core of programming is data structure, not algorithms. ——Rob Pike Description This article is based on the understanding … Read more
I am Lao Wen, an embedded engineer who loves learning.Follow me to become even better together! I remember when I first started working, a master told me that if you are not familiar with longjmp and setjmp, you should not call yourself a C language expert. At that time, I was half-convinced, but to move … Read more
In the previous article, we discussed the declaration and definition of pointers and other basic concepts. However, our understanding of pointers is still insufficient, so in this lesson, we will continue to learn about pointers. To reinforce our understanding, let’s first look at a classic pointer example code. Can you find the correct answer?Question: Now … Read more
Input Events to State Machine #include "stdio.h" #define EXECUTE_VOID(func) {if((func)!=NULL) (func());} typedef void(*select_machine_t)(void); typedef enum _event_index{ event_index_1 = 0, event_index_2, event_index_3, event_index_end} event_index_e; typedef enum _status_index{ status_index_1 = 0, status_index_2, status_index_end} status_index_e; void machine_1(void); void machine_2(void); void machine_3(void); void machine_4(void); select_machine_t select_machine[event_index_end][status_index_end] = { {machine_1, machine_2}, {NULL, machine_3}, {machine_4, NULL}}; void machine_1(void){ printf("machine_1\r\n"); } void … Read more
01 (Common Mistakes) Answer: D Explanation: For option C: Memory addresses can be accessed directly through pointers. For option D: Although there is no strict limit on the number of statements within a function in C, it is actually constrained by the compiler or system resources. 02 Answer: C Explanation: Omitted 03 Answer: A Explanation: … Read more
