# Macros

Macros are commands within the code that allow for customization of the Lua++ compiler’s behavior. To use a macro one would use the `--!` prefix followed by the name of the macro. These macros must be the first statement of the program. Otherwise, the compiler will throw an error. Here are some examples:

```lua
--!<macro>
print("hello")
```

The following segment will not compile successfully as there is a statement preceding the macro definition:

```lua
local v = 1 -- NO
--!<macro>
print("hello")
```