Conditional logic lets a PowerShell script make decisions. An If construct evaluates an expression that must produce $True or $False, then runs its script block only when the condition is true. section 5.2
Build a decision from these parts:
- Start with a mandatory If and a script block. section 5.2
- Add zero or more ElseIf branches when different conditions require different actions. section 5.2
- Remember that only the first true branch runs; later ElseIf expressions are not evaluated. section 5.2
- Use an optional Else block for the case where no preceding condition is true. section 5.2
- Prefer readable brace formatting, especially when blocks contain several commands; PowerShell has no End If statement. section 5.2
Choosing a connection protocol
A function can select DCOM when -Protocol is Dcom and use WSMan otherwise. This keeps the connection choice explicit while protecting the rest of the function from protocol-specific setup. section 10.1.2
Combining conditions
Use comparison and logical operators to express a complete rule, such as taking action when a process value is greater than 4 or less than 2. Put each comparison in parentheses for readability. section 5.2
If (<expression>) {
# code
} ElseIf (<expression>) {
# code
} ElseIf (<expression>) {
# code
} Else {
# code
}
Use this skeleton to map one condition, multiple alternatives, and a fallback action before filling in real commands. section 5.2
Apply the construct incrementally in reusable functions: start with one tested decision, then add more behavior. For example, a service-logon function can use If with ForEach to update one or more computers. section 10.1.2 section 10.5.2
