freepascal - 为什么 Free Pascal 打印 'NO' ？

Question

var
    a: Integer;  
begin 
    a:= 300;  
    if a in [100..500] then  
        WriteLn ('YES')    
    else  
        WriteLn ('NO')  
end.

Answer 1

根据 FreePascal documentation，Pascal 仅支持集合中 0 到 255 之间的数字.重要的部分在这里:

Each of the elements of SetType must be of type TargetType. TargetType can be any ordinal type with a range between 0 and 255. A set can contain at most 255 elements.

打开范围检查 {$R+} 将导致编译器警告您这些类型的错误。