不确定使用 Pascal 切换 [英] Unsure tabbing with Pascal

问题描述

我正在尝试标记一些代码，请有人检查以确保我已正确完成此操作(为简单起见更改了一些代码):

Hi I'm trying to tab some code, please could someone check to make sure I have done this correctly (Changed some code for simplicity):

begin
  if Password <> Database['Database']
    then showmessage ('Message')
    else
  if NewPassword <> Retype
    then showmessage ('Message')
    else
      begin
        if Message (yes, No, etc) =yes
          then
            begin
              List
              List
              List.post;
              showmessage ('Message')
            end
          else close;
      end;
end;

推荐答案

这是一个编码风格的问题，可能不会长久存在.:-)(编码风格在很大程度上取决于个人意见，并且有很多不同的风格.)无论如何，我会试一试.:-)

This is a coding style question, and may not survive here very long. :-) (Coding style is very much a matter of personal opinion, and there are an awful lot of different ones out there.) I'll give it a shot, anyway. :-)

我的做法略有不同.IMO，这清楚地向新程序员显示了 if..else 和 begin..end 的正确配对:

I'd do it slightly differently. IMO, this clearly shows the proper pairings of if..else and begin..end to a new programmer:

begin
  if Password <> Database['Database'] then
    showmessage ('Message')
  else 
    if NewPassword <> Retype then
      showmessage ('Message')
    else
    begin
      if Message (yes, No, etc) = yes then
      begin
        List;
        List;
        List.post;
        showmessage ('Message');
      end
      else
        close;
    end;
end;

在我自己的代码中，我仍然会做一些不同的事情(但只有很小的区别).我会将 else if password 移动到同一行(它减少了一级缩进，对我来说使代码流更清晰.我们有三种可能选项，并且清楚地显示了三个选项(if this、else if this、else this):

In my own code, I'd do it a little differently still (but only a minor difference). I'd move the else if password to the same line (it reduces one level of indent, and to me makes the flow of the code more clear. We have three possible options, and there are three options clearly shown (if this, else if this, else this):

begin
  if Password <> Database['Database'] then    // option 1
    showmessage ('Message')
  else if NewPassword <> Retype then          // option 2
    showmessage ('Message')
  else                                        // option 3
  begin
    if Message (yes, No, etc) = yes then
    begin
      List;
      List;
      List.post;
      showmessage ('Message');
    end
    else
      close;
  end;
end;

只有几个其他代码区域的格式有时会产生影响.我会尝试快速接触我能想到的尽可能多的人.

There are only a couple of other code areas where formatting sometimes makes a difference. I'll try to quickly touch as many of them as I can think of off-hand.

案例陈述:

case i of
  0: DoThingForZero;            // Only one line to execute for 0
  1: begin                      // Two things to do for 1
       DoSetupForOne;
       DoThingForOne;
     end;
  2: DoThingForTwo;
else                            // Handle anything other than 0, 1, 2
  DoThingsForOtherValues;
end;

While 语句:

while not Query1.Eof do
begin
  // Process each field in current record of table
  Query1.Next;  // Move to next row (easy to forget, infinite loop happens. :-)
end;

重复陈述:

i := 1;
repeat
  i := i + SomeFunctionResultReturningVariousValues();
until (i >  50)

For 循环:

for i := 0 to List.Count - 1 do
begin
  ProcessItem(List[i]);
end;

for i := List.Count - 1 downto 0 do
  List[i].Delete;

For..in 循环:

For..in loops:

for ch in SomeString do           // For each character in a string,
  WriteLn(ch, ' = ', Ord(ch));    // write the ordinal (numeric) value 
ReadLn;

尝试..最后:

SL := TStringList.Create;        // Create object/open file/whatever (resource)
try
  // Code using resource 
finally
  SL.Free;                       // Free the resource
end;

尝试..除外:

try
  // Do something that might raise an exception
except
  on E: ESomeVerySpecificException do
  begin
     // Handle very specific exception 
  end;
  on E: ESomeLessSpecificException do
  begin
    // Handle less specific exception
  end;
  else
    raise;
end;

Try..finally with try..except:

Try..finally with try..except:

SL := TStringList.Create;         // Allocate resource
try
  try
    // Do something that might raise exception
  except
    // Handle exception as above
  end;
finally
  SL.Free;                       // Free resource
end;

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