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The time now is 2026-08-09 08:12

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DOS批处理 & 脚本技术（批处理室） » Do these do anything, can they be removed?

Floor1　zwdeee	Posted 2008-07-27 19:00
初级用户　Posts 54　Credits 153
@echo off set a=0 for /f %%a in (你要搜索的文件.txt) do set a=%%a echo %a% Does “set a=0” here have no effect at all? Can it be omitted? Also: @echo off & setlocal set a= for /f "delims=" %%a in (sample.txt) do set a=%%a echo.%a% It seems the effect is the same even if “ & setlocal” and “set a=” are removed?

Floor2　HAT	Posted 2008-07-27 19:35
版主　Posts 5,017　Credits 9,023
Although variables in batch files do not have to be defined before use, initializing variables is a very good programming habit, hope you keep it!

Floor3　yangzhiyi	Posted 2008-07-27 22:50
中级用户　Posts 123　Credits 261
If a batch file uses multiple identical variables then you should keep the initialization.

Floor4　pusofalse	Posted 2008-07-28 01:36
银牌会员　Posts 646　Credits 1,604
The initial value of numeric variables is 0. Below, calculate 2 to the 10th power. for /l %%a in (1 1 10) do set/a a*=2 echo %a% It displays 0, because the initial value of a was not changed, so you need to define a beforehand. set a=1 OK, then the result is correct... Above is one small issue about the initial value.