它按照后进先出的原则存储数据，先进入的数据被压入栈底，最后的数据在栈顶，需要读数据的时候从栈顶开始弹出数据（最后一个数据被第一个读出来）。 -It is in accordance with the principle of LIFO store data, first enter the data is pushed onto the stack at the end, the last data in the top of the stack, you need to read data from the top of the stack began to pop up when the data (the last data is read out first.)