提高对char数组中指针语法理解

char arr[] = "Hello";
char *ptr = arr;
for (int i = 0; i < 6; i++) {
    printf("%c", *(ptr + i));
}

char *ptr = NULL;
if (ptr != NULL) {
    printf("%c", *ptr);
}

char *ptr = (char *)malloc(100 * sizeof(char));
// 使用 ptr
free(ptr);

#include <stdio.h>
#include <stdlib.h>

int main() {
    char arr[] = "Hello";
    char *ptr = arr;

    // 打印字符串
    for (int i = 0; i < 5; i++) {
        printf("%c", *(ptr + i));
    }
    printf("\n");

    // 动态分配内存
    char *dynamic_ptr = (char *)malloc(100 * sizeof(char));
    if (dynamic_ptr == NULL) {
        printf("Memory allocation failed\n");
        return 1;
    }
    strcpy(dynamic_ptr, "World");
    printf("%s\n", dynamic_ptr);

    // 释放内存
    free(dynamic_ptr);

    return 0;
}