Powershell if String.StartsWith() multiple strings

Question

I am trying to run some code if a string does not start with a certain character, however I can not get it to work with multiple characters.

This is the code that works fine.

if (-Not $recdata.StartsWith("1"))
{
    //mycode.
}

What I want is multiple checks like this:

if (-Not $recdata.StartsWith("1") -Or -Not $recdata.StartsWith("2"))
{
    //mycode.
}

But this does not work: it breaks the whole function even though PowerShell does not throw any errors.

We would need to understand where is your input coming from. Can you provide us with a sample input and your expected output(s)? — Santiago Squarzon
– Santiago Squarzon, Commented Jul 15, 2021 at 0:31
Data comes over TCP as text. What i want is when i send for example 1 to the script over TCP that it does not execute my code. It does work when i use the first example i posted. but when i try to exclude 1 and 2 the whole code doesnt work anymore and my script executes the code even though i send 1 or 2 — Robi SE.
– Robi SE., Commented Jul 15, 2021 at 0:43
If what you need is to not run your code neither when $recdata starts with "1", neither "2", then you should change the -Or for an -And — MundoPeter
– MundoPeter, Commented Jul 15, 2021 at 1:02
You can also do if( $recdata -match '^[^12]' ) { # your code if it does not start with 1 and 2 } — Santiago Squarzon
– Santiago Squarzon, Commented Jul 15, 2021 at 1:29
How could i add even more checks to this? just add a 3 after the 2 or? — Robi SE.
– Robi SE., Commented Jul 15, 2021 at 10:47

mklement0 · Accepted Answer · 2021-07-15 01:48:19Z

7

MundoPeter has pointed out the logic flaw in your approach - -or should be -and - and Santiago Squarzon has offered an alternative based on the regex-based -match operator.

Let me offer the following PowerShell-idiomatic solutions, taking advantage of the fact that PowerShell's operators offer negated variants simply by prepending not to their names:

$recdata[0] -notin '1', '2' # check 1st char of LHS against RHS array

$recdata -notlike '[12]*'   # check LHS against wildcard expression

$recdata -notmatch '^[12]'  # check LHS against regex

Collectives™ on Stack Overflow

Powershell if String.StartsWith() multiple strings

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related