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Groovy / Collections

Flatten nested collections

Learn Flatten nested collections in Groovy through a focused explanation, a dedicated topic-specific example, an engineering boundary, and a mastery check.

12 min read • Intermediate

Flatten nested collections is a focused Groovy lesson inside Collections. The example uses the construct named in the lesson directly rather than reusing a generic placeholder.

Trace the example from its inputs through Flatten nested collections and identify the behavior that would change if that construct were removed or replaced. Pay attention to the language-specific rules shown by the syntax, because neighboring lessons intentionally exercise different mechanisms.

Topic-specific example

groovy-0040-829fdc130d.groovy
groovy Try It Live 
def prices = [12, 5, 9]
def taxed = prices.collect { it * 1.1 }
println taxed
assert (1..4).sum() == 10
Edge case / engineering note

For Flatten nested collections, test one realistic boundary: empty data, invalid input, unavailable resources, lifetime/cleanup, type constraints, or concurrency timing where applicable. A successful happy path is not enough to prove the construct is used correctly.

Content source & attribution
Original Syntaxis Content · Original Syntaxis Content

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