Do...Until

Run a command block based on the results of a conditional test.

Syntax
 [:Loop_label] Do
 {
 command_block
 } while (condition)
or
 [:Loop_label] Do
 {
 command_block
 } until (condition)
Key
 condition If this evaluates to TRUE the loop {command_block} runs.
 when the loop has run once the condition is evaluated again
 command_block Commands, separated by commas, to run each time the loop repeats.
 :Loop_label An optional label than can be used to break or continue.

A Do..While loop continues as long as the condition is TRUE.
A Do..Until loop continues as long as the condition is FALSE. Until is an antonym of While.

As long as the condition is met, PowerShell will continue to rerun the {command_block} section unless interrupted by a break or continue statement.

Examples

Count to 10:

PS> Do { $val++ ; Write-Host $val } while($val -ne 10)

You can also use carriage returns instead of semi-colons:

PS> Do { $val++ 
 Write-Host $val
 } while($val -ne 10) 

"A quarrel is quickly settled when deserted by one party; there is no battle unless there be two" ~ Lucius Annaeus Seneca

Related PowerShell Cmdlets

Break statement
Continue statement
Do - Run a command block based on the results of a conditional test.
ForEach-Object - Loop for each object in the pipeline (foreach).
ForEach - Loop through values in the pipeline.
IF - Conditionally perform a command.
For - Loop through items that match a condition.
Switch - Multiple if statements.