501
votes

I'm trying to define and use a variable in a batch file. It looks like it should be simple:

@echo off

set location = "bob"
echo We're working with "%location%"

The output I get is the following:

We're working with ""

What's going on here? Why is my variable not being echo'd?

4

4 Answers

616
votes

The space before the = is interpreted as part of the name, and the space after it (as well as the quotation marks) are interpreted as part of the value. So the variable you’ve created can be referenced with %location %. If that’s not what you want, remove the extra space(s) in the definition.

281
votes

The spaces are significant. You created a variable named 'location ' with a value of
' "bob"'. Note - enclosing single quotes were added to show location of space.

If you want quotes in your value, then your code should look like

set location="bob"

If you don't want quotes, then your code should look like

set location=bob

Or better yet

set "location=bob"

The last syntax prevents inadvertent trailing spaces from getting in the value, and also protects against special characters like & | etc.

9
votes

input location.bat

@echo off
cls

set /p "location"="bob"
echo We're working with %location%
pause

output

We're working with bob

(mistakes u done : space and " ")

2
votes

Consider also using SETX - it will set variable on user or machine (available for all users) level though the variable will be usable with the next opening of the cmd.exe ,so often it can be used together with SET :

::setting variable for the current user
if not defined My_Var (
  set "My_Var=My_Value"
  setx My_Var My_Value
)

::setting machine defined variable
if not defined Global_Var (
  set "Global_Var=Global_Value"
  SetX Global_Var Global_Value /m
)

You can also edit directly the registry values:

User Variables: HKEY_CURRENT_USER\Environment

System Variables: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment

Which will allow to avoid some restrictions of SET and SETX like the variables containing = in their names.

3rd party edit

SETX.exe Set environment variables permanently,

SETX can be used to set Environment Variables for the machine (HKLM) or currently logged on user (HKCU):

Option /m

 /m
       Set the variable in the system environment HKLM.
       (The default is the local environment HKCU)

Another example

::setting variable for the current user
if not defined JAVAJDK (
  set "JAVAJDK=C:\Program Files\Java\jdk-13\bin"
  setx JAVAJDK "C:\Program Files\Java\jdk-13\bin"
)

In a command.exe you can use the variable like this cd %JAVAJDK%.