Learn Groovy higher-order functions. Groovy collect, inject, groupBy, collectEntries, and collectMany. 10+ tested examples with output on Groovy 5.x. “Give me a collection and a closure, and I will give you back a transformed world.” Abelson & Sussman, Structure and Interpretation of Computer Programs Last Updated: March 2026 | Tested on: Groovy 5.x, Java 17+ | Difficulty: Intermediate | Reading Time: 17 minutes The each loop is just the beginning – groovy collect, inject, groupBy, and their relatives form a ... Read More