The JAVA_HOME variable is a key component that is normally used by a wide variety of off
The following example shows how to see the JAVA_HOME defined on a system. Once the environment variable is defined, it can be accessed via the % sign. If you have variables that would be used across batch files, then it is always preferable to use environment variables. You will notice that the command echo %var% will not yield anything because after the ENDLOCAL statement, the ‘var’ variable will no longer exist. Hence, this variable will be destroyed as soon the ‘ENDLOCAL’ statement is executed. The ‘var‘ variable is defined in a local scope because it is enclosed between a ‘SETLOCAL’ and ‘ENDLOCAL’ block. The ‘globalvar’ is defined with a global scope and is available throughout the entire script. offįew key things to note about the above program. The following example shows the difference when local and global variables are set in the script. After calling SETLOCAL, any variable assignments revert upon calling ENDLOCAL, calling EXIT, or when execution reaches the end of file (EOF) in your script. Call the SETLOCAL command to make variables local to the scope of your script. By default, variables are global to your entire command prompt session. Normally, variable having a global scope can be accessed anywhere from a program whereas local scoped variables have a defined boundary in which they can be accessed.ĭOS scripting also has a definition for locally and globally scoped variables.
the section of code on which they can be accessed. In any programming language, there is an option to mark variables as having some sort of scope, i.e. The following example shows arithmetic operators can be used in batch off The output of the above program would be 15.Īll of the arithmetic operators work in batch files. We are adding those values and storing in the variable c.įinally, we are displaying the value of the variable c. We are first setting the value of 2 variables, a and b to 5 and 10 respectively. The following code shows a simple way in which numeric values can be set with the /A off In batch script, it is also possible to define a variable to hold a numeric value. To display the value of the variable, note that the variable needs to be enclosed in the % sign. In the above code snippet, a variable called message is defined and set with the value of "Hello World". The following example shows a simple way the set command can be used. A – This switch is used if the value needs to be numeric in nature. Value is the value which needs to be set against the variable. Variable-name is the name of the variable you want to set. Following is the syntax of the set command. The other way in which variables can be initialized is via the ‘set’ command. However, the fourth parameter would be ignored. The output would still remain the same as above. The above command produces the following output. If the above batch script is stored in a file called test.bat and we were to run the batch asįollowing is a screenshot of how this would look in the command prompt when the batch file is executed. The following example shows a batch file which accepts 3 command line arguments and echo’s them to the command line off The arguments can be called from the batch files through the variables %1, %2, %3, and so on. Command Line Argumentsīatch scripts support the concept of command line arguments wherein arguments can be passed to the batch file when invoked. One is for parameters which can be passed when the batch file is called and the other is done via the set command. There are two types of variables in batch files.