memset,allocate,sizeof,strlen,strcpy,strcat

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
int main() {
    // typedef struct Node{
    //     int data;
    //     struct Node* p;
    // }Node, *pNode;
    int array_i[1024];
    printf("%d\n", sizeof(array_i) / sizeof(int));
    char array_c[1024];
    printf("%d\n", sizeof(array_c));

    //字符指针
    char* p = "hello";
    printf("%s\n", p);
    char p2[] = "world";
    printf("%d\n", sizeof(p2)); //自带'0'
    printf("%d\n", strlen(p2)); //不带'0',strlen不管有没有'0'，只计算长度，不包括0
    char p3[] = { '1','2' };
    printf("%d\n", sizeof(p3)); //不带'0'
    //strlen 在计算长度的时候不会把结束符 '\x00' 计算在内，strcpy 在拷贝的时候会把 '\x00' 也算上，所以就会造成 off by one
    char p4[1024];
    memset(p4, 1, sizeof(p4));
    printf("%d\n", p4[0]);

    char p5[1024] = "string1";
    char p6[] = "string2";
    strcat(p5, p6);
    for (int i = 0; i < 20; i++)
        printf("%c", p5[i]);
    printf("\n%d", strlen(p5));

    //strcpy

    return 0;
}