You are not the first, who fell into the famous “delayed expansion trap” (and you won’t be the last). You need delayed expansion if you want to use a variable, that you changed in the same block (a block is a series of commands within parentheses (and )). Delayed variables are referenced with !var! instead … Read more
You missed something 😉 cmd expands variables when commands are parsed, not when they are run. It so happens that an if or for statement with a block ( … ) (or actually any block) counts as a single command in that case. So when you set variables inside a block and try using them … Read more
Look at the following examples… Example 1: The following code DOESN’T use delayed expansion, so the variables in the for loop are expanded only one time. This means that %Count% will always expand to 0 in each iteration of the loop, no matter what we do to it with the set command: @echo off set … Read more
I think you should understand what delayed expansion is. The existing answers don’t explain it (sufficiently) IMHO. Typing SET /? explains the thing reasonably well: Delayed environment variable expansion is useful for getting around the limitations of the current expansion which happens when a line of text is read, not when it is executed. The … Read more
Ok. I’ll try to be as clear as possible to not be misunderstood… In Windows Batch files a variable name should begin with a letter and may include any valid character, where valid characters are: #$'()*+,-.?@[]_`{}~ besides letters and digits. This means that from the cmd.exe point of view, SET NORMAL_NAME=123 is exactly the same … Read more
var2 is set, but the expansion in the line echo %var2% occurs before the block is executed. At this time var2 is empty. Therefore the delayedExpansion syntax exists, it uses ! instead of % and it is evaluated at execution time, not parse time. Please note that in order to use !, the additional statement … Read more