PowerShell DataGridView checkbox row cell value - winforms

Question

This is the function to check if checkbox is true winforms DataGridView:
function Install {
param (
# OptionalParameters
)
for($i=0;$i -lt $getAppsDataGrid.RowCount;$i++){
if($getAppsDataGrid.Rows[$i].Cells[3].Value -eq $true)
{
$i
$getAppsDataGrid.Rows[$i].Cells[$i].Value
write-host "cell #$i is checked"
#uncheck it
#$datagridview1.Rows[$i].Cells['exp'].Value=$false
}
else
{
#check it
#$datagridview1.Rows[$i].Cells['exp'].Value=$true
write-host "cell #$i is not-checked"
}
}
}
This is working so far. But I want the cell value from the current row. $getAppsDataGrid.Rows[$i].Cells[1].Value is not working in this function. But outside of this function it works. Also other things dont show in here like current var $i. Everything except "cell $i is checked / not checked is" irgnored
Output:
cell #0 is checked
cell #1 is checked
cell #2 is checked
cell #3 is not-checked
cell #4 is not-checked
cell #5 is not-checked
cell #6 is not-checked
cell #7 is not-checked
cell #8 is not-checked
cell #9 is not-checked
cell #10 is not-checked
cell #11 is not-checked

Answer 1

There is a difference between writing something to host and writing it in output (or returning it from function).
When you use Write-output $i or return $i or $i you are adding $i to the output stream, or result of the function. When calling the function if you capture the result in a variable, then the outputs will not print.
Look at this example:
function GetEvens {
for($i=0;$i -lt 10;$i++){
if($i%2 -eq 0)
{
$i
write-host "#$i is even"
}
else
{
write-host "#$i is odd"
}
}
}
$evens = GetEvens
It captures the output (return values) which are even numbers in $evens but write the string "#i is odd" or "#i is even" in host.

Answer 2

Inside your function, you are simply dumping $i and $getAppsDataGrid.Rows[$i].Cells[1].Value through down the pipeline, showing nothing in the console.
To write to console, use the Write-* cmdlets. This is why strings like cell #0 is checked DO show up in the console.
If you want your function to write out everything to the console, change it to something like
function Install {
param (
# OptionalParameters
)
for($i = 0; $i -lt $getAppsDataGrid.RowCount; $i++){
Write-Host "Checking row $i"
if($getAppsDataGrid.Rows[$i].Cells[3].Value) {
Write-Host "Value ($i,$i): {0}" -f $getAppsDataGrid.Rows[$i].Cells[$i].Value
Write-Host "cell #$i is checked"
#uncheck it
#$datagridview1.Rows[$i].Cells['exp'].Value=$false
}
else {
#check it
#$datagridview1.Rows[$i].Cells['exp'].Value=$true
Write-Host "cell #$i is not-checked"
}
}
}