Which is faster for substring detection, IF !A! !A:B=!, echo.!A!|find "!B!" or echo.!A!|findstr /c:"!B!" ?
Posted: 24 May 2024 00:30
Answer IF !A! !A:B=! is 4 times faster than the other two
10000 loops of the IF takes about 45 seconds, no matter how long the strings are, while the other two take about 2 minute and a half !
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Since I am writing a GetIndexSubstring and am still optimizing it.
I wanted to know which of these three methods to check if a string is inside another string was the fastest
So I wrote the following code to test
And the console output is
10000 loops of the IF takes about 45 seconds, no matter how long the strings are, while the other two take about 2 minute and a half !
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Since I am writing a GetIndexSubstring and am still optimizing it.
I wanted to know which of these three methods to check if a string is inside another string was the fastest
So I wrote the following code to test
Code: Select all
:IF-versus-FINDSTR
setlocal enabledelayedexpansion
Set "_IVF_Input=THIS IS a TEST"
Set "_IVF_Search=IS"
Set /a _IVF_count=10000
set "_IVF_callback_label=:IF-versus-FINDSTR-1"
GoTo :IF-versus-FINDSTR-loop-start
:IF-versus-FINDSTR-1
Set "_IVF_Input=THIS IS a TEST with many characters 012345689[7000 characters removed here for brevity]012345689"
Set "_IVF_Search=IS"
Set /a _IVF_count=10000
set "_IVF_callback_label=:IF-versus-FINDSTR-2"
GoTo :IF-versus-FINDSTR-loop-start
:IF-versus-FINDSTR-2
:IF-versus-FINDSTR-3
:IF-versus-FINDSTR-4
GoTo :EOF
:IF-versus-FINDSTR-loop-start
Set /a _IVF_index=1
echo start IF TEST %time% count %_IVF_count% search %_IVF_Search% input %_IVF_Input%
:IF-versus-FINDSTR-loop
set "_IVF_buffer=!_IVF_Input:%_IVF_Search%=!
if !_IVF_Input! EQU !_IVF_buffer! ( set "_IVF_result=true" ) else ( set "_IVF_result=false" )
Set /a _IVF_index+=1
if %_IVF_index% LSS %_IVF_count% GoTo :IF-versus-FINDSTR-loop
echo end IF TEST %time% count %_IVF_count% search %_IVF_Search% input %_IVF_Input%
:IF-versus-FIND-loop-loop-start
Set /a _IVF_index=1
echo start FIND TEST %time% count %_IVF_count% search %_IVF_Search% input %_IVF_Input%
:IF-versus-FIND-loop-loop
echo.!_IVF_Input!| find "!_IVF_Search!" >nul && ( set "_IVF_result=true" ) || ( set "_IVF_result=false" )
Set /a _IVF_index+=1
if %_IVF_index% LSS %_IVF_count% GoTo :IF-versus-FIND-loop-loop
echo end FIND TEST %time% count %_IVF_count% search %_IVF_Search% input %_IVF_Input%
:IF-versus-FINDSTR-loop-loop-loop-start
Set /a _IVF_index=1
echo start FINDSTR TEST %time% count %_IVF_count% search %_IVF_Search% input %_IVF_Input%
:IF-versus-FINDSTR-loop-loop-loop
echo.!_IVF_Input!| findstr /c:"!_IVF_Search!" >nul && ( set "_IVF_result=true" ) || ( set "_IVF_result=false" )
Set /a _IVF_index+=1
if %_IVF_index% LSS %_IVF_count% GoTo :IF-versus-FINDSTR-loop-loop-loop
echo end FINDSTR TEST %time% count %_IVF_count% search %_IVF_Search% input %_IVF_Input%
GoTo %_IVF_callback_label%
endlocal
GoTo :EOFCode: Select all
start IF TEST 2:11:42.63 count 10000 search IS input THIS IS a TEST
end IF TEST 2:12:27.97 count 10000 search IS input THIS IS a TEST
start FIND TEST 2:12:27.97 count 10000 search IS input THIS IS a TEST
end FIND TEST 2:15:04.46 count 10000 search IS input THIS IS a TEST
start FINDSTR TEST 2:15:04.46 count 10000 search IS input THIS IS a TEST
end FINDSTR TEST 2:17:32.97 count 10000 search IS input THIS IS a TEST
start IF TEST 2:17:32.97 count 10000 search IS input THIS IS a TEST with many characters 012345689[OUTPUT TRUNKATED HERE]012345689
end IF TEST 2:18:18.84 count 10000 search IS input THIS IS a TEST with many characters 012345689[OUTPUT TRUNKATED HERE]012345689
start FIND TEST 2:18:18.84 count 10000 search IS input THIS IS a TEST with many characters 012345689[OUTPUT TRUNKATED HERE]012345689
end FIND TEST 2:20:50.41 count 10000 search IS input THIS IS a TEST with many characters 012345689[OUTPUT TRUNKATED HERE]012345689
start FINDSTR TEST 2:20:50.41 count 10000 search IS input THIS IS a TEST with many characters 012345689[OUTPUT TRUNKATED HERE]012345689
end FINDSTR TEST 2:23:29.77 count 10000 search IS input THIS IS a TEST with many characters 012345689[OUTPUT TRUNKATED HERE]012345689