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DOS批处理 & 脚本技术（批处理室） » [Help] Question about dynamic environment variables

Floor1　pusofalse	Posted 2008-06-09 01:55
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When I was bored, I tested a short piece of code. Like this... @echo off&setlocal enabledelayedexpansion echo %time% set time=a&echo !time! pause echo %time% echo %time% echo %time% pause Changing time to random gives the same result. Aren't system variables like these all dynamically calculated in real time~? Why is it that after assigning a value manually, it no longer changes in real time?

Floor2　knoppix7	Posted 2008-06-18 18:08
银牌会员　Posts 634　Credits 1,287　From cmd.exe
In the set /? help there is: If the user explicitly defines a variable with one of these names, then that definition will override the dynamic one described below:

Floor3　HAT	Posted 2008-06-18 21:51
版主　Posts 5,017　Credits 9,023
If you've learned C, it should be fairly easy to understand. You can think of it as a local variable overriding a global variable.