对与结构相关的 C 语句的含义感到困惑

Question

我无法理解这句话的意思，谁能给我解释一下。

这是我的结构:

struct dataT
{
    int m;
};

struct stack
{
    int top;
    struct dataT items[STACKSIZE];
} st;

这是我感到困惑的说法。不太明白是什么意思:

st.items[st.top].m

Answer 1

st: An object of type struct stack
st.top: Top of stack
st.items: Array of stack items
st.items[st.top]: Top item of stack
st.items[st.top].m: member m of top item of stack

              st
  +-----------------------+
  |           top         |  st.top
  +-----------------------+
  | +-------------------+ |
  | |                   |m|  st.item[0]
  | +-------------------+ |
  +-----------------------+
  | +-------------------+ |
  | |                   |m|  st.item[1]
  | +-------------------+ |
  +-----------------------+
  .                       .
  .                       .
  .                       .
  +-----------------------+
  | +-------------------+ |
  | |                   |m| st.item[STACKSIZE - 1]
  | +-------------------+ |
  +-----------------------+

如果将 3 和 5 压入堆栈，它看起来像(堆栈向下增长)

              st
  +-----------------------+
  |            1          |  st.top = 1
  +-----------------------+
  |            3          |  st.item[0].m = 3
  +-----------------------+
  |            5          |  st.item[1].m = st.item[st.top].m = 5
  +-----------------------+
  .                       .
  .                       .
  .                       .
  +-----------------------+
  | xxxxxxxxxxxxxxxxxxx   |
  +-----------------------+