How to reduce value of variable in batch?

-1

I need to reduce value of variable by 3 but it says Missing operand

:(1-3)

set /p speed=">> "

if %speed% geq 4 goto duzo

if %speed% leq 0 goto malo

set x=4

set /a x==%x%-%speed%

I tried that too:

set /a speed==4-%speed%

Edit:

Now I have a problem with

choice

comand. I'm using windows 10. When I'm adding for example

echo Do you want to try again? 

choice /t 10 /c yn  /d n

program stops as it comes and I cannot do anything to it

edited Jan 3 at 6:52

asked Jan 2 at 16:47

maxmarsz

285

1

Nowhere in the help file for the SET command does it say that a double equals is a valid operator. Where did you find this example on the Internet? You can simplify the assignment like this: set /a speed-=4.

– Squashman
Jan 2 at 17:46

There's no problem with your choice command, and tested on win10 it's okay.

– Tiw
Jan 4 at 3:22

Okay now it's working

– maxmarsz
Jan 4 at 5:30

I think you need to use big letters in arguments

– maxmarsz
Jan 4 at 5:31

@maxmarsz What did you do to make it working? I just copied your lower case command and it worked fine.

– Tiw
Jan 5 at 3:30

|
show 1 more comment

-1

I need to reduce value of variable by 3 but it says Missing operand

:(1-3)

set /p speed=">> "

if %speed% geq 4 goto duzo

if %speed% leq 0 goto malo

set x=4

set /a x==%x%-%speed%

I tried that too:

set /a speed==4-%speed%

Edit:

Now I have a problem with

choice

comand. I'm using windows 10. When I'm adding for example

echo Do you want to try again? 

choice /t 10 /c yn  /d n

program stops as it comes and I cannot do anything to it

edited Jan 3 at 6:52

asked Jan 2 at 16:47

maxmarsz

285

1

Nowhere in the help file for the SET command does it say that a double equals is a valid operator. Where did you find this example on the Internet? You can simplify the assignment like this: set /a speed-=4.

– Squashman
Jan 2 at 17:46

There's no problem with your choice command, and tested on win10 it's okay.

– Tiw
Jan 4 at 3:22

Okay now it's working

– maxmarsz
Jan 4 at 5:30

I think you need to use big letters in arguments

– maxmarsz
Jan 4 at 5:31

@maxmarsz What did you do to make it working? I just copied your lower case command and it worked fine.

– Tiw
Jan 5 at 3:30

|
show 1 more comment

-1

I need to reduce value of variable by 3 but it says Missing operand

:(1-3)

set /p speed=">> "

if %speed% geq 4 goto duzo

if %speed% leq 0 goto malo

set x=4

set /a x==%x%-%speed%

I tried that too:

set /a speed==4-%speed%

Edit:

Now I have a problem with

choice

comand. I'm using windows 10. When I'm adding for example

echo Do you want to try again? 

choice /t 10 /c yn  /d n

program stops as it comes and I cannot do anything to it

edited Jan 3 at 6:52

asked Jan 2 at 16:47

maxmarsz

285

I need to reduce value of variable by 3 but it says Missing operand

:(1-3)

set /p speed=">> "

if %speed% geq 4 goto duzo

if %speed% leq 0 goto malo

set x=4

set /a x==%x%-%speed%

I tried that too:

set /a speed==4-%speed%

Edit:

Now I have a problem with

choice

comand. I'm using windows 10. When I'm adding for example

echo Do you want to try again? 

choice /t 10 /c yn  /d n

program stops as it comes and I cannot do anything to it

batch-file windows-10

edited Jan 3 at 6:52

asked Jan 2 at 16:47

maxmarsz

285

edited Jan 3 at 6:52

asked Jan 2 at 16:47

maxmarsz

285

edited Jan 3 at 6:52

asked Jan 2 at 16:47

maxmarsz

285

asked Jan 2 at 16:47

maxmarsz

285

asked Jan 2 at 16:47

maxmarsz

285

1

Nowhere in the help file for the SET command does it say that a double equals is a valid operator. Where did you find this example on the Internet? You can simplify the assignment like this: set /a speed-=4.

– Squashman
Jan 2 at 17:46

There's no problem with your choice command, and tested on win10 it's okay.

– Tiw
Jan 4 at 3:22

Okay now it's working

– maxmarsz
Jan 4 at 5:30

I think you need to use big letters in arguments

– maxmarsz
Jan 4 at 5:31

@maxmarsz What did you do to make it working? I just copied your lower case command and it worked fine.

– Tiw
Jan 5 at 3:30

|
show 1 more comment

1

Nowhere in the help file for the SET command does it say that a double equals is a valid operator. Where did you find this example on the Internet? You can simplify the assignment like this: set /a speed-=4.

– Squashman
Jan 2 at 17:46

There's no problem with your choice command, and tested on win10 it's okay.

– Tiw
Jan 4 at 3:22

Okay now it's working

– maxmarsz
Jan 4 at 5:30

I think you need to use big letters in arguments

– maxmarsz
Jan 4 at 5:31

@maxmarsz What did you do to make it working? I just copied your lower case command and it worked fine.

– Tiw
Jan 5 at 3:30

Nowhere in the help file for the SET command does it say that a double equals is a valid operator. Where did you find this example on the Internet? You can simplify the assignment like this: set /a speed-=4.

– Squashman
Jan 2 at 17:46

There's no problem with your choice command, and tested on win10 it's okay.

– Tiw
Jan 4 at 3:22

Okay now it's working

– maxmarsz
Jan 4 at 5:30

I think you need to use big letters in arguments

– maxmarsz
Jan 4 at 5:31

@maxmarsz What did you do to make it working? I just copied your lower case command and it worked fine.

– Tiw
Jan 5 at 3:30

|
show 1 more comment

2 Answers
2

active

oldest

votes

If you're wanting only a limited number of valid options, you should really consider using the Choice command. Unlike Set /P which allows for any or no entry, Choice will alert and prevent invalid input.

Set "velocidad=4"

Choice /C 123 /M "reduccion de velocidad: "

Set /A velocidad -= %ErrorLevel%

For usage information, enter Choice /? at the Command Prompt. And similarly for the Set command, Set /?.

answered Jan 2 at 18:12

Compo

16.8k3927

I dont know why but choice command just dont work for me

– maxmarsz
Jan 2 at 21:05

When I add it program just stops as it comes and I cannot do anything to it

– maxmarsz
Jan 2 at 21:06

1

It won't work if you're still using the seventeen+ year old Operating System formerly known as Windows XP, as it wasn't part of that product. But I'm sure that you'd have mentioned that as part of your question proper, or at least use an appropriate title and/or tag to inform us you were using Windows XP if that was the case. Have you opened a Command Prompt window and entered Choice /? yet, if it works, the problem is elsewhere in something you haven't told us about, and therefore out of the scope of this question.

– Compo
Jan 2 at 22:17

So Im working on windows 10 and yes I checkd the choice /? and it works. But when I use it in my program it just stops

– maxmarsz
Jan 3 at 5:41

@maxmarsz, there is absolutely nothing wrong with the three lines I've posted. Please update the main body of your question to provide us with the actual code you're now having issues with. We cannot help you fix the problem if we don't know what it is.

– Compo
Jan 3 at 6:25

add a comment |

Just

set /a speed=4-speed

When you use /a, you don't need % anymore. also you used == instead of =.

If you want x-speed, then it's:

set /a speed=x-speed

edited Jan 2 at 16:50

answered Jan 2 at 16:48

Tiw

4,24861630

2

Thank you a lot It works :D

– maxmarsz
Jan 2 at 16:50

add a comment |

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2 Answers
2

active

oldest

votes

2 Answers
2

active

oldest

votes

Set "velocidad=4"

Choice /C 123 /M "reduccion de velocidad: "

Set /A velocidad -= %ErrorLevel%

For usage information, enter Choice /? at the Command Prompt. And similarly for the Set command, Set /?.

answered Jan 2 at 18:12

Compo

16.8k3927

I dont know why but choice command just dont work for me

– maxmarsz
Jan 2 at 21:05

When I add it program just stops as it comes and I cannot do anything to it

– maxmarsz
Jan 2 at 21:06

1

It won't work if you're still using the seventeen+ year old Operating System formerly known as Windows XP, as it wasn't part of that product. But I'm sure that you'd have mentioned that as part of your question proper, or at least use an appropriate title and/or tag to inform us you were using Windows XP if that was the case. Have you opened a Command Prompt window and entered Choice /? yet, if it works, the problem is elsewhere in something you haven't told us about, and therefore out of the scope of this question.

– Compo
Jan 2 at 22:17

So Im working on windows 10 and yes I checkd the choice /? and it works. But when I use it in my program it just stops

– maxmarsz
Jan 3 at 5:41

@maxmarsz, there is absolutely nothing wrong with the three lines I've posted. Please update the main body of your question to provide us with the actual code you're now having issues with. We cannot help you fix the problem if we don't know what it is.

– Compo
Jan 3 at 6:25

add a comment |

Set "velocidad=4"

Choice /C 123 /M "reduccion de velocidad: "

Set /A velocidad -= %ErrorLevel%

For usage information, enter Choice /? at the Command Prompt. And similarly for the Set command, Set /?.

answered Jan 2 at 18:12

Compo

16.8k3927

I dont know why but choice command just dont work for me

– maxmarsz
Jan 2 at 21:05

When I add it program just stops as it comes and I cannot do anything to it

– maxmarsz
Jan 2 at 21:06

1

It won't work if you're still using the seventeen+ year old Operating System formerly known as Windows XP, as it wasn't part of that product. But I'm sure that you'd have mentioned that as part of your question proper, or at least use an appropriate title and/or tag to inform us you were using Windows XP if that was the case. Have you opened a Command Prompt window and entered Choice /? yet, if it works, the problem is elsewhere in something you haven't told us about, and therefore out of the scope of this question.

– Compo
Jan 2 at 22:17

So Im working on windows 10 and yes I checkd the choice /? and it works. But when I use it in my program it just stops

– maxmarsz
Jan 3 at 5:41

@maxmarsz, there is absolutely nothing wrong with the three lines I've posted. Please update the main body of your question to provide us with the actual code you're now having issues with. We cannot help you fix the problem if we don't know what it is.

– Compo
Jan 3 at 6:25

add a comment |

Set "velocidad=4"

Choice /C 123 /M "reduccion de velocidad: "

Set /A velocidad -= %ErrorLevel%

For usage information, enter Choice /? at the Command Prompt. And similarly for the Set command, Set /?.

answered Jan 2 at 18:12

Compo

16.8k3927

Set "velocidad=4"

Choice /C 123 /M "reduccion de velocidad: "

Set /A velocidad -= %ErrorLevel%

For usage information, enter Choice /? at the Command Prompt. And similarly for the Set command, Set /?.

answered Jan 2 at 18:12

Compo

16.8k3927

answered Jan 2 at 18:12

Compo

16.8k3927

answered Jan 2 at 18:12

Compo

16.8k3927

answered Jan 2 at 18:12

Compo

16.8k3927

I dont know why but choice command just dont work for me

– maxmarsz
Jan 2 at 21:05

When I add it program just stops as it comes and I cannot do anything to it

– maxmarsz
Jan 2 at 21:06

1

It won't work if you're still using the seventeen+ year old Operating System formerly known as Windows XP, as it wasn't part of that product. But I'm sure that you'd have mentioned that as part of your question proper, or at least use an appropriate title and/or tag to inform us you were using Windows XP if that was the case. Have you opened a Command Prompt window and entered Choice /? yet, if it works, the problem is elsewhere in something you haven't told us about, and therefore out of the scope of this question.

– Compo
Jan 2 at 22:17

So Im working on windows 10 and yes I checkd the choice /? and it works. But when I use it in my program it just stops

– maxmarsz
Jan 3 at 5:41

@maxmarsz, there is absolutely nothing wrong with the three lines I've posted. Please update the main body of your question to provide us with the actual code you're now having issues with. We cannot help you fix the problem if we don't know what it is.

– Compo
Jan 3 at 6:25

add a comment |

I dont know why but choice command just dont work for me

– maxmarsz
Jan 2 at 21:05

When I add it program just stops as it comes and I cannot do anything to it

– maxmarsz
Jan 2 at 21:06

1

It won't work if you're still using the seventeen+ year old Operating System formerly known as Windows XP, as it wasn't part of that product. But I'm sure that you'd have mentioned that as part of your question proper, or at least use an appropriate title and/or tag to inform us you were using Windows XP if that was the case. Have you opened a Command Prompt window and entered Choice /? yet, if it works, the problem is elsewhere in something you haven't told us about, and therefore out of the scope of this question.

– Compo
Jan 2 at 22:17

So Im working on windows 10 and yes I checkd the choice /? and it works. But when I use it in my program it just stops

– maxmarsz
Jan 3 at 5:41

@maxmarsz, there is absolutely nothing wrong with the three lines I've posted. Please update the main body of your question to provide us with the actual code you're now having issues with. We cannot help you fix the problem if we don't know what it is.

– Compo
Jan 3 at 6:25

I dont know why but choice command just dont work for me

– maxmarsz
Jan 2 at 21:05

When I add it program just stops as it comes and I cannot do anything to it

– maxmarsz
Jan 2 at 21:06

It won't work if you're still using the seventeen+ year old Operating System formerly known as Windows XP, as it wasn't part of that product. But I'm sure that you'd have mentioned that as part of your question proper, or at least use an appropriate title and/or tag to inform us you were using Windows XP if that was the case. Have you opened a Command Prompt window and entered Choice /? yet, if it works, the problem is elsewhere in something you haven't told us about, and therefore out of the scope of this question.

– Compo
Jan 2 at 22:17

So Im working on windows 10 and yes I checkd the choice /? and it works. But when I use it in my program it just stops

– maxmarsz
Jan 3 at 5:41

@maxmarsz, there is absolutely nothing wrong with the three lines I've posted. Please update the main body of your question to provide us with the actual code you're now having issues with. We cannot help you fix the problem if we don't know what it is.

– Compo
Jan 3 at 6:25

add a comment |

Just

set /a speed=4-speed

When you use /a, you don't need % anymore. also you used == instead of =.

If you want x-speed, then it's:

set /a speed=x-speed

edited Jan 2 at 16:50

answered Jan 2 at 16:48

Tiw

4,24861630

2

Thank you a lot It works :D

– maxmarsz
Jan 2 at 16:50

add a comment |

Just

set /a speed=4-speed

When you use /a, you don't need % anymore. also you used == instead of =.

If you want x-speed, then it's:

set /a speed=x-speed

edited Jan 2 at 16:50

answered Jan 2 at 16:48

Tiw

4,24861630

2

Thank you a lot It works :D

– maxmarsz
Jan 2 at 16:50

add a comment |

Just

set /a speed=4-speed

When you use /a, you don't need % anymore. also you used == instead of =.

If you want x-speed, then it's:

set /a speed=x-speed

edited Jan 2 at 16:50

answered Jan 2 at 16:48

Tiw

4,24861630

Just

set /a speed=4-speed

When you use /a, you don't need % anymore. also you used == instead of =.

If you want x-speed, then it's:

set /a speed=x-speed

edited Jan 2 at 16:50

answered Jan 2 at 16:48

Tiw

4,24861630

edited Jan 2 at 16:50

answered Jan 2 at 16:48

Tiw

4,24861630

answered Jan 2 at 16:48

Tiw

4,24861630

answered Jan 2 at 16:48

Tiw

4,24861630

2

Thank you a lot It works :D

– maxmarsz
Jan 2 at 16:50

add a comment |

2

Thank you a lot It works :D

– maxmarsz
Jan 2 at 16:50

Thank you a lot It works :D

– maxmarsz
Jan 2 at 16:50

add a comment |

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