String Map GStringImpl

string-map-3.groovy

#!/usr/bin/groovy

s = "something"
t = "${s} else"

println "${s}".getClass().name                       //org.codehaus.groovy.runtime.GStringImpl

Map mm = ["${s}": "${t}"]
println mm["${s}"].getClass().name                  //org.codehaus.groovy.runtime.NullObject
println mm["${s}"]                                  //null

Map nn = ["something": "something else"]
println nn[s].getClass().name                       //java.lang.String
println nn[s]                                       //something else