Learn Groovy - 10 Code Examples & CST Typing Practice Test

Groovy is a powerful, dynamic JVM language that integrates seamlessly with Java, offering concise syntax, scripting capabilities, functional programming patterns, and strong support for automation, DSL creation, and Gradle build scripts. It blends Java familiarity with Python/Ruby-like expressiveness.

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Groovy Counter and Theme Toggle Groovy Simple Calculator Groovy Factorial Groovy Fibonacci Sequence Groovy List Comprehension Groovy Map Filtering Groovy Anonymous Closures Groovy Reduce Example Groovy Zip Lists Groovy Tuple Destructuring

Learn GROOVY with Real Code Examples

Updated Nov 19, 2025

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Code Sample Descriptions

Groovy Counter and Theme Toggle

def count = 0
def isDark = false

def updateUI = {
    println "Counter: $count"
    println "Theme: ${isDark ? 'Dark' : 'Light'}"
}

def increment = { count++; updateUI() }
def decrement = { count--; updateUI() }
def reset = { count = 0; updateUI() }
def toggleTheme = { isDark = !isDark; updateUI() }

// Simulate actions
updateUI()
increment()
increment()
toggleTheme()
decrement()
reset()

Demonstrates a simple counter with theme toggling using Groovy variables and console output.

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Groovy Simple Calculator

def add = { a, b -> a + b }
def subtract = { a, b -> a - b }
def multiply = { a, b -> a * b }
def divide = { a, b -> a / b }

println "Add 5 + 3: ${add(5,3)}"
println "Subtract 5 - 3: ${subtract(5,3)}"
println "Multiply 5 * 3: ${multiply(5,3)}"
println "Divide 6 / 2: ${divide(6,2)}"

Basic arithmetic operations using closures.

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Groovy Factorial

def factorial
factorial = { n ->
    if (n <= 1) return 1
    else return n * factorial(n-1)
}

println "Factorial of 5: ${factorial(5)}"

Recursive factorial function.

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Groovy Fibonacci Sequence

def fibonacci
fibonacci = { n ->
    if (n == 0) return 0
    if (n == 1) return 1
    return fibonacci(n-1) + fibonacci(n-2)
}

(0..9).each { println fibonacci(it) }

Generate Fibonacci numbers recursively.

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Groovy List Comprehension

def numbers = 1..10
def squares = numbers.findAll { it % 2 == 0 }.collect { it * it }
println squares

Square even numbers using collection operations.

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Groovy Map Filtering

def scores = [Alice:10, Bob:5, Charlie:12]
def highScores = scores.findAll { k,v -> v >= 10 }
println highScores

Filter a map based on values.

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Groovy Anonymous Closures

def add = { x, y -> x + y }
println add(3,7)

Using closures as anonymous functions.

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Groovy Reduce Example

def numbers = [1,2,3,4,5]
def sum = numbers.inject(0) { acc, val -> acc + val }
println sum

Sum elements of a list using inject (reduce).

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Groovy Zip Lists

def list1 = [1,2,3]
def list2 = [4,5,6]
def sums = [list1, list2].transpose().collect { it.sum() }
println sums

Combine two lists element-wise using transpose.

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Groovy Tuple Destructuring

def pair = [3,7]
def (x,y) = pair
println x + y

Destructuring a tuple and performing operations.

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Frequently Asked Questions about Groovy

What is Groovy?

What are the primary use cases for Groovy?

Gradle build scripts. Jenkins declarative & scripted pipelines. Automation & scripting on the JVM. Rapid backend prototyping. Testing frameworks (Spock). Domain-specific language (DSL) creation

What are the strengths of Groovy?

Concise compared to Java. Perfect for Gradle/Jenkins automation. Dynamic or static typing flexibility. Rich testing ecosystem (Spock). Excellent for DSLs & config-driven systems

What are the limitations of Groovy?

Slower than pure Java due to dynamic typing. Performance overhead. Less mainstream than Java/Kotlin. Smaller ecosystem vs Java. Tooling sometimes less polished

How can I practice Groovy typing speed?

CodeSpeedTest offers 10+ real Groovy code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.

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Code Sample Descriptions

Groovy Counter and Theme Toggle

def count = 0
def isDark = false

def updateUI = {
    println "Counter: $count"
    println "Theme: ${isDark ? 'Dark' : 'Light'}"
}

def increment = { count++; updateUI() }
def decrement = { count--; updateUI() }
def reset = { count = 0; updateUI() }
def toggleTheme = { isDark = !isDark; updateUI() }

// Simulate actions
updateUI()
increment()
increment()
toggleTheme()
decrement()
reset()

Demonstrates a simple counter with theme toggling using Groovy variables and console output.

Let’s Try →

Groovy Simple Calculator

def add = { a, b -> a + b }
def subtract = { a, b -> a - b }
def multiply = { a, b -> a * b }
def divide = { a, b -> a / b }

println "Add 5 + 3: ${add(5,3)}"
println "Subtract 5 - 3: ${subtract(5,3)}"
println "Multiply 5 * 3: ${multiply(5,3)}"
println "Divide 6 / 2: ${divide(6,2)}"

Basic arithmetic operations using closures.

Let’s Try →

Groovy Factorial

def factorial
factorial = { n ->
    if (n <= 1) return 1
    else return n * factorial(n-1)
}

println "Factorial of 5: ${factorial(5)}"

Recursive factorial function.

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Groovy Fibonacci Sequence

def fibonacci
fibonacci = { n ->
    if (n == 0) return 0
    if (n == 1) return 1
    return fibonacci(n-1) + fibonacci(n-2)
}

(0..9).each { println fibonacci(it) }

Generate Fibonacci numbers recursively.

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Groovy List Comprehension

def numbers = 1..10
def squares = numbers.findAll { it % 2 == 0 }.collect { it * it }
println squares

Square even numbers using collection operations.

Let’s Try →

Groovy Map Filtering

def scores = [Alice:10, Bob:5, Charlie:12]
def highScores = scores.findAll { k,v -> v >= 10 }
println highScores

Filter a map based on values.

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Groovy Anonymous Closures

def add = { x, y -> x + y }
println add(3,7)

Using closures as anonymous functions.

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Groovy Reduce Example

def numbers = [1,2,3,4,5]
def sum = numbers.inject(0) { acc, val -> acc + val }
println sum

Sum elements of a list using inject (reduce).

Let’s Try →

Groovy Zip Lists

def list1 = [1,2,3]
def list2 = [4,5,6]
def sums = [list1, list2].transpose().collect { it.sum() }
println sums

Combine two lists element-wise using transpose.

Let’s Try →

Groovy Tuple Destructuring

def pair = [3,7]
def (x,y) = pair
println x + y

Destructuring a tuple and performing operations.

Let’s Try →

Frequently Asked Questions about Groovy

What is Groovy?

What are the primary use cases for Groovy?

Gradle build scripts. Jenkins declarative & scripted pipelines. Automation & scripting on the JVM. Rapid backend prototyping. Testing frameworks (Spock). Domain-specific language (DSL) creation

What are the strengths of Groovy?

Concise compared to Java. Perfect for Gradle/Jenkins automation. Dynamic or static typing flexibility. Rich testing ecosystem (Spock). Excellent for DSLs & config-driven systems

What are the limitations of Groovy?

Slower than pure Java due to dynamic typing. Performance overhead. Less mainstream than Java/Kotlin. Smaller ecosystem vs Java. Tooling sometimes less polished

How can I practice Groovy typing speed?

CodeSpeedTest offers 10+ real Groovy code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.