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使用GPT 3.5 学习C语言: 25个简单代码让你了解 C 语言基本语法
以下是一些学习C语言的常用代码示例，涵盖了各种语法和概念：
Hello World
#include
int main() { printf("Hello, World!\n"); return 0; }
变量和数据类型
#include
int main() { int age = 20; float weight = 65.5; char grade = 'A'; printf("Age: %d\n", age); printf("Weight: %.2f\n", weight); printf("Grade: %c\n", grade); return 0; }
输入输出
#include
int main() { int num; printf("Enter a number: "); scanf("%d", &num); printf("You entered: %d\n", num); return 0; }
条件语句
#include
int main() { int num; printf("Enter a number: "); scanf("%d", &num); if (num > 0) {
printf("Positive number\n");} else if (num < 0) {
printf("Negative number\n");} else {
printf("Zero\n");} return 0; }
循环语句
#include
int main() { int i; for (i = 1; i <= 5; i++) {
printf("%d ", i);} printf("\n");
int j = 1; while (j <= 5) {
printf("%d ", j); j++;} printf("\n");
int k = 1; do {
printf("%d ", k); k++;} while (k <= 5); printf("\n");
return 0; }
数组
#include
int main() { int numbers[5] = {1, 2, 3, 4, 5}; printf("First element: %d\n", numbers[0]); printf("Second element: %d\n", numbers[1]);
int i; for (i = 0; i < 5; i++) {
printf("%d ", numbers[i]);} printf("\n");
return 0; }
函数
#include
int add(int a, int b) { return a + b; }
int main() { int result = add(2, 3); printf("Result: %d\n", result); return 0; }
字符串
#include
int main() { char name[20] = "John Doe"; printf("Name: %s\n", name);
char message[50]; printf("Enter a message: "); fgets(message, sizeof(message), stdin); printf("You entered: %s\n", message);
return 0; }
结构体
#include
typedef struct { char name[20]; int age; } Person;
int main() { Person person; strcpy(person.name, "John Doe"); person.age = 25;
printf("Name: %s\n", person.name); printf("Age: %d\n", person.age);
return 0; }
指针
#include
int main() { int num = 10; int *ptr = #
printf("Value: %d\n", num); printf("Address: %p\n", &num); printf("Pointer value: %p\n", ptr); printf("Dereference pointer: %d\n", *ptr);
return 0; }
文件操作
#include
int main() { FILE *file = fopen("file.txt", "w"); if (file != NULL) {
fprintf(file, "This is some text."); fclose(file); printf("File created and written successfully.\n");} else {
printf("Error opening file.\n");}
return 0; }
动态内存分配
#include #include
int main() { int *numbers = (int *)malloc(5 * sizeof(int)); if (numbers != NULL) {
numbers[0] = 1; numbers[1] = 2; numbers[2] = 3; numbers[3] = 4; numbers[4] = 5; int i; for (i = 0; i < 5; i++) { printf("%d ", numbers[i]); } free(numbers);} else {
printf("Memory allocation failed.\n");}
return 0; }
枚举
#include
typedef enum { MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY } Day;
int main() { Day today = TUESDAY;
switch (today) {
case MONDAY: printf("It's Monday.\n"); break; case TUESDAY: printf("It's Tuesday.\n"); break; case WEDNESDAY: printf("It's Wednesday.\n"); break; case THURSDAY: printf("It's Thursday.\n"); break; case FRIDAY: printf("It's Friday.\n"); break; case SATURDAY: printf("It's Saturday.\n"); break; case SUNDAY: printf("It's Sunday.\n"); break;}
return 0; }
递归
#include
int factorial(int n) { if (n <= 1) {
return 1;} else {
return n * factorial(n - 1);} }
int main() { int num = 5; int result = factorial(num); printf("Factorial of %d is %d.\n", num, result);
return 0; }
多文件编程
链表
#include #include
typedef struct Node { int data; struct Node *next; } Node;
void insert(Node **head, int data) { Node *newNode = (Node *)malloc(sizeof(Node)); newNode->data = data; newNode->next = NULL;
if (*head == NULL) {
*head = newNode;} else {
Node *temp = *head; while (temp->next != NULL) { temp = temp->next; } temp->next = newNode;} }
void display(Node *head) { Node *temp = head; while (temp != NULL) {
printf("%d ", temp->data); temp = temp->next;} printf("\n"); }
int main() { Node *head = NULL; insert(&head, 1); insert(&head, 2); insert(&head, 3); display(head);
return 0; }
函数指针
#include
int add(int a, int b) { return a + b; }
int subtract(int a, int b) { return a - b; }
int main() { int (*ptr)(int, int);
ptr = add; printf("Addition: %d\n", ptr(2, 3));
ptr = subtract; printf("Subtraction: %d\n", ptr(5, 3));
return 0; }
位运算
#include
int main() { unsigned int a = 5; // 0000 0101 unsigned int b = 3; // 0000 0011
unsigned int result;
result = a & b; // 0000 0001 (位与) printf("Bitwise AND: %u\n", result);
result = a | b; // 0000 0111 (位或) printf("Bitwise OR: %u\n", result);
result = a ^ b; // 0000 0110 (位异或) printf("Bitwise XOR: %u\n", result);
result = ~a; // 1111 1010 (位取反) printf("Bitwise NOT: %u\n", result);
result = a << 2; // 0001 0100 (左移) printf("Left Shift: %u\n", result);
result = a >> 1; // 0000 0010 (右移) printf("Right Shift: %u\n", result);
return 0; }
宏定义
#include
#define PI 3.14159 #define SQUARE(x) ((x) * (x))
int main() { float radius = 2.5; float area = PI * SQUARE(radius);
printf("Area: %.2f\n", area);
return 0; }
错误处理
#include #include #include
int main() { FILE *file = fopen("nonexistent.txt", "r"); if (file == NULL) {
printf("Error opening file: %s\n", strerror(errno));} else {
// 文件操作 fclose(file);}
return 0; }
以上示例涵盖了C语言中的更多语法和概念，希望对你的学习有所帮助。记得不断练习和探索，以加深对C语言的理解和掌握。
当然，以下是更多的C语言代码示例，涵盖了更多的语法和概念：
位字段
#include
struct Flags { unsigned int isRed : 1; unsigned int isGreen : 1; unsigned int isBlue : 1; };
int main() { struct Flags f; f.isRed = 1; f.isGreen = 0; f.isBlue = 1;
printf("Red: %u\n", f.isRed); printf("Green: %u\n", f.isGreen); printf("Blue: %u\n", f.isBlue);
return 0; }
类型转换
#include
int main() { int a = 10; double b = 3.14;
double result = (double)a + b;
printf("Result: %.2f\n", result);
return 0; }
函数参数默认值
#include
void greet(char *name, char *message) { if (name == NULL) {
name = "Guest";} printf("Hello, %s! %s\n", name, message); }
int main() { greet(NULL, "Welcome to the program."); greet("John", "Nice to meet you.");
return 0; }
结构体指针与箭头操作符
#include #include
typedef struct { int x; int y; } Point;
int main() { Point *p = (Point *)malloc(sizeof(Point)); p->x = 2; p->y = 3;
printf("x: %d\n", p->x); printf("y: %d\n", p->y);
free(p);
return 0; }
逗号运算符
#include
int main() { int a = 2, b = 3, c = 4, result;
result = (a * b) + (c - a), a++, b++, c++;
printf("Result: %d\n", result); printf("a: %d\n", a); printf("b: %d\n", b); printf("c: %d\n", c);
return 0; }
以上示例涵盖了C语言中的更多语法和概念，希望对你的学习有所帮助。记得不断练习和探索，以加深对C语言的理解和掌握。
希望以上代码示例能帮助你学习C语言的基础知识。请注意，这只是一小部分C语言的语法示例，还有很多其他的语法和概念等待你去探索和学习。
当然，以下是更多的C语言代码示例，涵盖了更多的语法和概念：
以上示例涵盖了C语言中的一些常用语法和概念，希望对你的学习有所帮助。记得不断练习和探索，以加深对C语言的理解和掌握。
当然，以下是更多的C语言代码示例，涵盖了更多的语法和概念：
file1.c:
#include <stdio.h>
void sayHello() {
printf("Hello from file1.c!\n");
}
file2.c:
#include <stdio.h>
void sayHello(); // 函数声明
int main() {
sayHello();
return 0;
}
编译和链接两个文件：
gcc file1.c file2.c -o program
以上示例涵盖了C语言中的更多语法和概念，希望对你的学习有所帮助。记得不断练习和探索，以加深对C语言的理解和掌握。
当然，以下是更多的C语言代码示例，涵盖了更多的语法和概念：