使用(动态范围)
procedure Main is
X, Y, Z : Integer;
procedure Suba is
A, Y, X : Integer;
begin
-- Suba body
end;
procedure Subb is
A, B, Z : Integer;
begin
-- Subb body
end;
procedure Subc
A, X, W : Integer;
begin
--- Subc body
end;
begin
--- Main body
end;
问题是:对于调用序列,说明在最后一个过程 Main 调用 Suba 的执行过程中哪些变量是可见的;Suba调用Subb;Subb 调用 Subc
为什么是答案: Suba:A,X,W Subb:B,Z Subc:Y
我试过解决它,我只是不明白这是怎么回事,谁能提供解释