Summary
This chapter introduced writing scripts and functions, including brief guidance on establishing a style, followed by an exploration of the small differences between scripts, functions, and script blocks.
You can use parameters to accept user input for scripts, functions, and script blocks. The param block can be used to define the list of parameters.
Named blocks are used when acting on pipeline input. Each block executes at a different point in the pipeline lifecycle. The function and filter keywords use a different default named block, but otherwise have identical functionality. The begin block in all commands in a pipeline executes before a pipeline starts, the process block executes once for each value passed from one function to another, and the end block executes once for each function after the last pipeline value is passed.
The cleanup block was very briefly introduced as an up-and-coming feature, hopefully one that will make it into PowerShell...