How to access map in template string?

I want to use values from gradle.properties that should go into a template string.

A naive first:

println("${project.properties[somekey]}")

doesn't work: Unresolved reference: somekey

So, quotes required?

println("${project.properties[\"somekey\"]}")

is completely broken syntax: Expecting an expression for the first .

I couldn't find any example how to do this, yet the official documentation says expressions.

Question: is it possible to access a map in string template, and if so, how?

Solution

Yes and as follows:

"${project.properties["someKey"]}"

assuming the Map has the following signature: Map<String, Any?> (or Map<Any...)

Alternatives:

"${project.properties.getValue("someKey")}"
"${project.properties.getOrElse("someKey") { "lazy-evaluation-default-value" }}"
"${project.properties.getOrDefault("someKey", "someFixedDefaultValue")}"

Basically all the code you put in the ${} is just plain Kotlin code... no further quoting/escaping required, except for the dollar sign $ itself, e.g. use "\$test" if you do not want it to be substituted with a variable named test or """${"$"}test""" if you use a raw string

Note that in this println case the following would have sufficed as well (which also goes for all the shown alternatives above. You may omit the outer surrounding quotes and ${} altogether):

println(project.properties["someKey"])