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A string is an ordered collection of characters.

You can compare strings using conditional commands in batch files, namely, if, if-else, and for commands. Strings may contain spaces and special characters, which can cause errors in the batch file when executed normally.

Also, if the string contains double quotes, it may cause errors.

This tutorial will show you different ways to compare strings in batch files using if, if-else, and for commands.

Using if and if-else commands for string comparison in batch files

The if command performs conditional operations and logical comparisons between a set value and an expected value. It can check if a file exists, compare strings, and even check for errors.

Using the if command to compare strings

Let us take an example to check if the strings are equal or not. If they are equal, it will display the output using the echo command.

@echo off
SetLocal

set string1="Hello World"
set string2="Hello World"

if %string1% == %string2% (echo "Both the strings are equal")
cmd /k

Output:

Using if-else command to compare strings

@echo off
SetLocal

set string1="Hello World"
set string2="HELLO WORLD"
set string3="Hello World"


if %string1% == %string2% (echo string 1 and string 2 are equal echo the string is %string2%) else if %string1% == %string3% (echo string1 and string 3 are equal
echo the string is %string3%) else (echo all strings are different)
cmd /k

Output:

Notice:

1. Do not put spaces between brackets.
2. When strings or variables contain spaces or special characters, enclose them in double quotes.

With the if command, you can use /Ito do a case-insensitive string comparison and not run the command if the condition is false.

You can also use comparison operators such as EQU (equal to), NEQ (not equal to), LSS (less than), LEQ (less than or equal to), GTR (greater than or equal to), GEQ (greater than or equal to) to compare values. However, these operators cannot be used to compare strings.

Use if-else command to compare strings containing double quotes

If the string or variable contains double quotes, use the SetLocal command to enable delayed expansion. Use ! instead of ".

The same code looks like this:

@echo off
SetLocal EnableDelayedExpansion

set string1="Hello "World""
set string2=""HELLO WORLD""
set string3="Hello World"

if !string1! == !string2! (echo "string 1 and string 2 are equal") else if !string1! == !string3! (echo "string1 and string 3 are equal") else (echo "All strings are different")
cmd /k

Output:

Using for loop for string comparison in batch file

The for command is used to run a specified command for each file in a set of files.

Shows the syntax for the for command in a batch file.

for {%%|%}<variable> in (<set>) do <command> [<commandlineoptions>]

Let's take an example where we have to compare strings to display the Windows OS version:

@echo off
SetLocal EnableDelayedExpansion
for /f "usebackq tokens=1 delims=" %%I in ("C:\Users\Aastha Gas Harda\Desktop\testfile1.txt") do (
set string=%%I
echo %%I
if "%%~I" == "HelloWorld" (echo "match found") else (echo "match not found")
)
PAUSE

Output:

In the above example, a for loop is used to compare the string values. If the string value is equal to HelloWorld, it will display the output as a match found.

delimsspecifies the delimiter set, and tokens specifies which tokens in each line will be passed to the for loop. Whenever we use quotes in a for loop, we must use usebackq.

So, we have discussed different ways to compare strings in batch files. In addition to comparing strings, these conditional commands can also be used to find specified values ​​or text from a text file or a log file.