PowerShell inherits by default variables downstream so subsequent scopes can "see" the parent variables. If you want to turn off variable inheritance altogether, you should use the prefix "private:." This way, variables will only work in the scope in which they are defined, and will neither inherit upstream or downstream:
$private:a = 1
Function test {
"variable a contains $a"
$a = 2
"variable a contains $a"
}
test
variable a contains
variable a contains 2
$a
1
Function test {
"variable a contains $a"
$a = 2
"variable a contains $a"
}
test
variable a contains
variable a contains 2
$a
1
You should note that defining a variable as private will not overwrite an existing variable. So, if you had previously defined a variable "a" without the private: prefix, you would not be able to turn it into a private variable. To make sure, you should either start a new fresh PowerShell environment, or delete the variable before creating your private variable:
Remove-Variable a -ErrorAction SilentlyContinue
