# 第9步：1個字的區域變數

到上一章為止，我們成功做出了可以進行四則運算的編譯器。在本章，我們要對該語言進行擴充，讓其可以使用變數。具體來說，我們的目標是要可以編譯如下含有變數的複數行的程式：

```c
a = 3;
b = 5 * 6 - 8;
a + b / 2;
```

我們把最後一行算式的結果作為程式整體的計算結果。這樣的語言，和只能計算四則運算的語言比起來，是不是可以說非常有「真正的語言」的氛圍了呢？

本章中，會先說明變數該實作成什麼樣子，再接著一步步將變數實作出來。


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