#include 
    
     #include 
     
      #include 
      
       int main() {    int32_t len = 10;    int32_t arr[len];//arr[0] 访问数组第一个元素    // clear array 清除数组 C中数组被创建时会有内存数据    for (int a = 0; a < len; a++) {        arr[a] = 0;    }    for (int32_t i = 0; i < len; i++) {        printf("index %d,and value is %d\n", i, arr[i]);    }    //数组初始化    int arra[] = {1, 3, 4, 5, 8, 9};    for (int i = 0; i < 6; ++i) {        printf("%d\n", arra[i]);    }    //创建二维数组    int array[3][4];    //clear arr    for (int i = 0; i < 3; i++) {        for (int j = 0; j < 4; j++) {            array[i][j] = 0;        }    }    printf("%d\n", array[1][1]);    for (int i = 0; i < 3; i++) {        for (int j = 0; j < 4; j++) {            printf("index(%d,%d),%d\n", i, j, array[i][j]);        }    }    //定义初始化    int array34[3][4] = {
    {1, 2,  3,  4},                         {5, 6,  7,  8},                         {9, 10, 11, 12}};    for (int i = 0; i < 3; i++) {        for (int j = 0; j < 4; j++) {            printf("index(%d,%d),%d\n", i, j, array34[i][j]);        }    }    //字符数组    char str[10] = {'H', 'e', 'l', 'l', 'o', '\0'};//  \0  此时系统认为字符串结尾    printf("String length : %ld，and string is %s\n", strlen(str), str);    memset(str, 0, 10);//字符数组清零    printf("String length : %ld，and string is %s\n", strlen(str), str);    //遍历    char string[] = "Hello World";    for (int i = 0; i < 11; ++i) {        printf("(index:%d)%c\n", i, string[i]);    }    return 0;}