Error when casting Temperature value to E-Mail

[rossko57]

There’s a bit about formatting at the bottom of this post

Working with Number:Temperature Items in rules

openHAB provides Quantity Type features, which can seem baffling. On top of that, Temperature type Quantities have a few quirks all of their own. These notes intend to guide the rules author. I’ve shown work examples in DSL rules language, see below for other scripts examples. All have similar features, if different syntax. Knowing what can be done is half the battle. What is a Quantity Type? Simply, Item states and rule variables may contain Quantities - that just means a number AND a unit …

example

var message = "Temperature is " + (tempItemC.state as QuantityType<Temperature>).format("%.1f%unit%")

“as Number” will not work because it comes with the units string which cannot be processed by decimal formatters like “%.2f”
“as QuantityType” gives you a units-friendly formatter.