01 The ASCII value of the digit character ‘0’ is 48. Given the following program: main() { char a=’1′,b=’2′; printf(“%c,”,b++); printf(“%d\n”,b-a); } The output of the program is: A) 3,2 B) 25,2 C) 2,2 D) 2,25 Answer: C Explanation: printf(“%c, b++): The initial value of b is ‘2’ (ASCII value 50); b++ is a post-increment, … Read more
01 Read the following program: void swap(char *x, char *y) { char t; t=*x; *x=*y; *y=t; } main() { char *s1=”abc”, *s2=”123″; swap(s1,s2); printf(“%s,%s\n”,s1,s2); } The output of the program is A) 123,abc B) abc,123 C) 1bc,a23 D) 321,cba Answer: C Analysis: The function swap works as follows: t = *x; saves the character pointed … Read more
01 Observe the following statement: char str1[10], str2[10] = {“books”}; The correct statement that can assign the string “books” to the array str1 is A) str1 = {“Books”}; B) strcpy(str1, str2); C) str1 = str2; D) strcpy(str2, str1); Answer: B Explanation: For option A: Correct, using the standard library function to copy the string. For … Read more
01 The followingcannot be defined as a user identifier: A) man B) _0 C) _int D) sizeof Answer: D Explanation: Among the given options, sizeof is a keyword in C language used to calculate the number of bytes occupied by a data type or variable. Since keywords cannot be used as user identifiers, The naming … Read more
Embedded Linux: A Comprehensive Guide to Pointers This article aims to summarize the learning of pointers in C language. If you like it, feel free to follow, as I will continue to update knowledge related to Embedded Linux. 1. The Relationship Between Pointers and Arrays 1. What is a Pointer? Like data types such as … Read more
Of course! Arrays are one of the most fundamental and commonly used data structures in C language. Understanding the underlying principles of arrays not only helps you write efficient programs but also lays a solid foundation for learning pointers, memory management, and more. 1. What is an Array? An array is a group of contiguous … Read more
This is a very critical and often confused knowledge point in C language: <span>char*</span>, character arrays (such as <span>char str[]</span>), and the relationship between strings. Let’s thoroughly clarify their essence, differences, and connections. 1. Basic Concepts of the Three Term Meaning <span>char*</span> Character pointer, pointing to the address of one (or more) <span>char</span> type variables … Read more
In the C language, pointers are one of the most fundamental, powerful, and easily confused concepts. They are not only tools for accessing memory but also play a crucial role in arrays, functions, structures, and many other areas. Below, I will guide you to fully understand the essence, types, uses, and examples of C language … Read more
Hello everyone, I am Xiao Feng Ge. This will be a series of articles related to the C language. In the previous article, we learned why we should use C language to develop operating systems. In this article, we will look at how C language controls hardware. The Design Philosophy of C Language The design … Read more
Pointers Detailed Explanation (Pointers） In the C programming language, a pointer is a powerful tool that allows you to directly manipulate memory addresses. Understanding pointers is not only key to writing good C programs but also fundamental to grasping core concepts such as memory management, arrays, and function parameter passing. 1. What is a Pointer? … Read more