I am coding in PowerShell 5.1 and have run across an odd issue when using Read-Host in a loop. For some reason, when I input something into Read-Host as per the code below, I always get it outputted on my PowerShell ISE console. Is there a way to flush the input buffer so that this doesn’t happen?

Code:

function Test-Read{
    for ($num = 1 ; $num -le 3 ; $num++){
     Read-Host -Prompt "Test Prompt"
    }
}

Output:

Test Prompt: a
a
Test Prompt: b
b
Test Prompt: c
c

Thanks,
Aurora

>Solution :

In PowerShell, all output from individual statements will "bubble up" to the caller (and eventually the screen buffer) unless suppressed or assigned.

Assign the string output from Read-Host to a variable, or cast the results of the call to [void]:

function Test-Read{
    for ($num = 1 ; $num -le 3 ; $num++){
        # $null is a special automatic variable - assigning to it won't affect it, much like piping to NUL in cmd or `/dev/null` on a UNIX/POSIX system
        $null = Read-Host -Prompt "Test Prompt"
    }
}

or

function Test-Read{
    for ($num = 1 ; $num -le 3 ; $num++){
        [void](Read-Host -Prompt "Test Prompt")
    }
}