Variables in ms dos batch files

One is for parameters which can be passed when the batch file is called and the other is done via the set command. Batch scripts support the concept of command line arguments wherein arguments can be passed to the batch file when invoked. Following is a screenshot of how this would look in the command prompt when the batch file is executed.

Following is the syntax of the set command. In the above code snippet, a variable called message is defined and set with the value of "Hello World". In batch script, it is also possible to define a variable to hold a numeric value. All of the arithmetic operators work in batch files. Viewed 20k times. Improve this question. Patrick Cuff Btw, what version of the command processor are you using?

What do you get when you enter 'ver' at the prompt? It makes a difference. Windows 98 [Version 4. Neither has Windows 9x. Add a comment. Active Oldest Votes. Improve this answer. Felix Dombek Update It's been a long time since I had to get a batch file working under such an old OS version, but I wouldn't be surprised if redirection was incompatible with for back in the day.

It is also possible to declare your variable using indexes so you may retrieve specific information. This will create multiple variables, with the illusion of an array:. Note that in the example above, you cannot reference var without stating what the desired index is, because var does not exist in its own.

This example also uses setlocal enabledelayedexpansion in conjunction with the exclamation points at! You can view more information about this in the Variable Substitution Scope Documentation. The second line is not working within a command block used for example on an IF condition or on a FOR loop as delayed expansion would be needed instead of standard environment variable expansion.

The Windows command interpreter does not support bit integer values or floating point values in arithmetic expressions. Using quotation marks to eliminate spaces In order to prevent spaces, use quotation marks around the entire assignment; the variable name and value. But this behaviour does mean that you cannot change a variable's value inside a block!

Advanced variable substitution Now, an advanced technique. Declare multiple variables When multiple variables are defined at the beginning of the batch, a short definition form may be used by employing a replacement string.

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