如何在定义局部变量时赋初始值

局部变量不像全局变量可赋初始值, 但可以通过编译指令把指定类型的常量当作变量用, 如:
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const
{$J+}
num: Integer = 1;
{$J-}
begin
Inc(num);
ShowMessage(IntToStr(num)); {2}
end;

//或者写作:
const
{$WRITEABLECONST ON}
num: Integer = 1;
{$WRITEABLECONST OFF}
begin
Inc(num);
ShowMessage(IntToStr(num)); {2}
end;