In this tutorial, you will learn about decision making structures that are the batch file if else statements.
If else statement: Introduction |
If else statement syntax |
Batch if else examples |
Basically programming logic is all about True (1) or False (0). Like any other programming language, batch file if else statements facilitate us to make a decision between true/false or multiple options by imposing a particular condition.
– Syntax
if (condition) dosomething
:: For if..else if
if (condition) (statement1) else (statement2)
So, as the syntax signifies, first a condition is checked and if true, the corresponding statements are executed in the batch file if statement. As for batch file if else
, first a condition of if statement is checked and if true, the statement1
is executed else statement2
is executed.
Here is a flowchart to highlight the concept of if else
statement.
Now that we have known about how batch file if else works, let’s go through some examples.
To know in depth and details about batch file variables, go through this article.
SET /A a=2
SET /A b=3
SET name1=Aston
SET name2=Martin
:: Using if statement
IF %a%==2 echo The value of a is 2
IF %name2%==Martin echo Hi this is Martin
:: Using if else statements
IF %a%==%b% (echo Numbers are equal) ELSE (echo Numbers are different)
IF %name1%==%name2% (echo Name is Same) ELSE (echo Name is different)
PAUSE
Now this will generate following output.
@echo OFF
::If var is not defined SET var = hello
IF "%var%"=="" (SET var=Hello)
:: This can be done in this way as well
IF NOT DEFINED var (SET var=Hello)
Either way, it will set var
to 'Hello'
as it is not defined previously.
EXIST
command is used to check if a file exists or not. Read this article to know details of EXIST and all the other batch file commands.
@echo OFF
::EXIST command is used to check for existence
IF EXIST D:\abc.txt ECHO abc.txt found
IF EXIST D:\xyz.txt (ECHO xyz.txt found) ELSE (ECHO xyz.txt not found)
PAUSE
Now, let’s assume we have "abc.txt"
in D drive and "xyz.txt"
doesn’t exist in D: , then it will generate following output.
So, that’s all about batch file if else statements. We hope you didn’t have a hard time learning about it and hopefully, by this time, you will know how to use if else
in batch file scripting.