Athul Prakash (age 16 at the time) gave a logical idea for how to implement an OR test by negating the conditions in IF statements and then using the ELSE clause as the location to put the code that requires execution. I thought to myself that there are however two else clauses usually needed since he is suggesting using two IF statements, and so the executed code needs to be written twice. However, if a GOTO is used to skip past the required code, instead of writing ELSE clauses the code for execution only needs to be written once.

下面是一个可测试的例子，我将如何实现Athul Prakash的否定逻辑来创建一个OR。

在我的例子中，如果某人有坦克执照或者正在服兵役，他就可以开坦克。在两个提示中输入true或false，你将能够看到逻辑是否允许你驾驶坦克。

@ECHO OFF
@SET /p tanklicence=tanklicence:
@SET /p militaryservice=militaryservice:

IF /I NOT %tanklicence%==true IF /I NOT %militaryservice%==true GOTO done

ECHO I am driving a tank with tanklicence set to %tanklicence% and militaryservice set to %militaryservice%

:done

PAUSE

IF语句不支持逻辑运算符AND和OR。 级联IF语句构成隐式连词:

IF Exist File1.Dat IF Exist File2.Dat GOTO FILE12_EXIST_LABEL

如果存在File1.Dat和File2.Dat，则跳转到标签FILE12_EXIST_LABEL。

参见:IF /?

试试否定操作数“not”!

好吧，如果你可以使用嵌套的“if”对if语句执行“AND”操作(参考前面的答案)，那么你可以对“if not”做同样的事情来执行“or”操作。

如果你还没有完全明白，继续往下读。否则，就不要浪费时间，回到编程中去。

就像嵌套的“if”只有在所有条件为真时才被满足一样，嵌套的“if not”只有在所有条件为假时才被满足。这类似于你想要对'or'操作数做的事情，不是吗?

即使嵌套的“if not”中的任何一个条件为真，整个语句仍然不满足。因此，你可以连续使用否定的“if”，记住条件语句的主体应该是你想要做的，如果所有嵌套的条件都是假的。你真正想要给出的主体应该在else语句下。

如果你还是不明白事情的真相，对不起，我16岁了，我只能解释这么多了。

Athul Prakash (age 16 at the time) gave a logical idea for how to implement an OR test by negating the conditions in IF statements and then using the ELSE clause as the location to put the code that requires execution. I thought to myself that there are however two else clauses usually needed since he is suggesting using two IF statements, and so the executed code needs to be written twice. However, if a GOTO is used to skip past the required code, instead of writing ELSE clauses the code for execution only needs to be written once.

下面是一个可测试的例子，我将如何实现Athul Prakash的否定逻辑来创建一个OR。

在我的例子中，如果某人有坦克执照或者正在服兵役，他就可以开坦克。在两个提示中输入true或false，你将能够看到逻辑是否允许你驾驶坦克。

@ECHO OFF
@SET /p tanklicence=tanklicence:
@SET /p militaryservice=militaryservice:

IF /I NOT %tanklicence%==true IF /I NOT %militaryservice%==true GOTO done

ECHO I am driving a tank with tanklicence set to %tanklicence% and militaryservice set to %militaryservice%

:done

PAUSE

如果你有兴趣在一个语句中写一个If +AND/OR，那么它没有任何一个。但是，你仍然可以将if与&&/||和(/)语句组合在一起，以实现你想在一行中w/o任何额外变量和w/o if-else块复制(TRUE和FALSE代码段的单个echo命令):

@echo off
    
setlocal
    
set "A=1" & set "B=2" & call :IF_AND
set "A=1" & set "B=3" & call :IF_AND
set "A=2" & set "B=2" & call :IF_AND
set "A=2" & set "B=3" & call :IF_AND
    
echo.
    
set "A=1" & set "B=2" & call :IF_OR
set "A=1" & set "B=3" & call :IF_OR
set "A=2" & set "B=2" & call :IF_OR
set "A=2" & set "B=3" & call :IF_OR
    
exit /b 0
    
:IF_OR
( ( if %A% EQU 1 ( type nul>nul ) else type 2>nul ) || ( if %B% EQU 2 ( type nul>nul ) else type 2>nul ) || ( echo.FALSE-& type 2>nul ) ) && echo TRUE+
    
exit /b 0
    
:IF_AND
( ( if %A% EQU 1 ( type nul>nul ) else type 2>nul ) && ( if %B% EQU 2 ( type nul>nul ) else type 2>nul ) && echo.TRUE+ ) || echo.FALSE-

    
exit /b 0

更统一的版本:

@echo off

setlocal

set "A=1" & set "B=2" & ( call :IF_AND "%%A%% EQU 1" "%%B%% EQU 2" && echo TRUE+ ) || echo FALSE-
set "A=1" & set "B=3" & ( call :IF_AND "%%A%% EQU 1" "%%B%% EQU 2" && echo TRUE+ ) || echo FALSE-
set "A=2" & set "B=2" & ( call :IF_AND "%%A%% EQU 1" "%%B%% EQU 2" && echo TRUE+ ) || echo FALSE-
set "A=2" & set "B=3" & ( call :IF_AND "%%A%% EQU 1" "%%B%% EQU 2" && echo TRUE+ ) || echo FALSE-

echo.

set "A=1" & set "B=2" & ( call :IF_OR "%%A%% EQU 1" "%%B%% EQU 2" && echo TRUE+ ) || echo FALSE-
set "A=1" & set "B=3" & ( call :IF_OR "%%A%% EQU 1" "%%B%% EQU 2" && echo TRUE+ ) || echo FALSE-
set "A=2" & set "B=2" & ( call :IF_OR "%%A%% EQU 1" "%%B%% EQU 2" && echo TRUE+ ) || echo FALSE-
set "A=2" & set "B=3" & ( call :IF_OR "%%A%% EQU 1" "%%B%% EQU 2" && echo TRUE+ ) || echo FALSE-

exit /b 0

:IF_OR
if %~1 ( exit /b 0 ) else if %~2 ( exit /b 0 ) else exit /b 1
exit /b -1

:IF_AND
if %~1 ( if %~2 ( exit /b 0 ) else exit /b 1 ) else exit /b 1
exit /b -1

输出:

TRUE+
FALSE-
FALSE-
FALSE-
    
TRUE+
TRUE+
TRUE+
FALSE-

诀窍在于type命令，它删除/设置errorlevel，从而处理到下一个命令的方式。

你可以用嵌套条件做和:

if %age% geq 2 (
    if %age% leq 12 (
        set class=child
    )
)

or:

if %age% geq 2 if %age% leq 12 set class=child

你可以用一个单独的变量:

set res=F
if %hour% leq 6 set res=T
if %hour% geq 22 set res=T
if "%res%"=="T" (
    set state=asleep
)

注意，这个答案是针对cmd批处理语言定制的，在Windows中可以找到。你提到了“DOS批处理”，但是，基于几点，我认为前者的选择是一个安全的赌注(1)。

如果你真的是指原始的MS-DOS批处理语言，你应该记住If语句要简单得多，你可能需要使用If语句的块…Goto表示控制流，而不是(例如)括号或其他。

(1)以下几点支持:

The presence of the cmd and windows-console tags; Prior experience of some people failing to recognise the very real difference between cmd and MS-DOS batch languages, and conflating DOC with the cmd terminal window; The question using the more generic "DOS" rather than specifically "MS-DOS" (where "DOS" could possibly be any disk operating system; The fact this is Stack Overflow rather than the retro-computing sister site, where a question about MS-DOS would be way more appropriate (I'm often on that site as well, it's nice for those of us who remember and appreciate computer history); and The (eventual) acceptance of the answer by the original asker, indicating that the solution worked.