C语言 的 数组

int main(int argc, const char * argv[])

{

    int numbers[3];

    numbers[0] = 1;

    numbers[1] = 2;

    numbers[2] = 3;

    printf("sizeof(numbers) is = %lu\n",sizeof(numbers));

    printf("sizeof(numbers[0])is = %lu\n",sizeof(numbers[0]));

    for (int i= 0; i<sizeof(numbers)/sizeof(numbers[0]); i++)

    {

        printf("numbers[%d] = %d\n",i,numbers[i]);

    }

    return 0;

}

sizeof(numbers) is = 12

sizeof(numbers[0]) is = 4

numbers[0] = 1

numbers[1] = 2

numbers[2] = 3

 

虽然只初始化了第一个元素，但其他元素也同时初始化为0了。

sizeof(numbers) ,得到数组中所有元素长度之和

sizeof(numbers[0])，得到一个元素的大小