C语言指针学习笔记：示例代码摘录

代码：

#include <stdio.h>void swap(int *, int *);int strlen1(char *);int strlen2(char []);void strcopy(char *, char *);int main() {int m = 12;int n = 23;printf("%d %d\n", m, n);swap(&m, &n);printf("%d %d\n", m, n);int len = strlen1("Hello");printf("%d\n", len);len = strlen2("Hello");printf("%d\n", len);char a[] = "Hello World 1";char b[] = "1234567890";printf("%s\n", a);strcopy(a, b);printf("%s\n", a);return 0;}void swap(int *a, int *b) {int c = *a;*a = *b;*b = c;}int strlen1(char *str) {int i = 0;while (*(str+i) != '\0') {i++;}return i;}int strlen2(char str[]) {int i = 0;while (str[i] != '\0') {i++;}return i;}void strcopy(char *s, char *p) {while ((*s++ == *p++) != '\0');}