// Here's a basic example.
if (7 % 2 == 0) {
    println "7 is even"
} else {
    println "7 is odd"
}

// You can have an `if` statement without an else.
if (8 % 4 == 0) {
    println "8 is divisible by 4"
}

// Logical operators like `&&` and `||` are often
// useful in conditions.
if (8 % 2 == 0 || 7 % 2 == 0) {
    println "either 8 or 7 are even"
}

// A statement can precede conditionals; any variables
// declared in this statement are available in the current
// and all subsequent branches.
def num = 9
if (num < 0) {
    println "$num is negative"
} else if (num < 10) {
    println "$num has 1 digit"
} else {
    println "$num has multiple digits"
}

def result = (7 % 2 == 0) ? "7 is even" : "7 is odd"
println result

def nullableValue = null
def nonNullValue = nullableValue ?: "default value"
println nonNullValue

Branching with `if` and `else` in Groovy is straightforward.

// Here's a basic example.
if (7 % 2 == 0) {
    println "7 is even"
} else {
    println "7 is odd"
}

// You can have an `if` statement without an else.
if (8 % 4 == 0) {
    println "8 is divisible by 4"
}

// Logical operators like `&&` and `||` are often
// useful in conditions.
if (8 % 2 == 0 || 7 % 2 == 0) {
    println "either 8 or 7 are even"
}

// A statement can precede conditionals; any variables
// declared in this statement are available in the current
// and all subsequent branches.
def num = 9
if (num < 0) {
    println "$num is negative"
} else if (num < 10) {
    println "$num has 1 digit"
} else {
    println "$num has multiple digits"
}To run this Groovy script, save it to a file (e.g., `if_else.groovy`) and execute it using the `groovy` command:
$ groovy if_else.groovy
7 is odd
8 is divisible by 4
either 8 or 7 are even
9 has 1 digitNote that in Groovy, parentheses around conditions are optional, but they're often used for clarity. Braces are required for multi-line blocks but can be omitted for single-line statements.
Groovy also supports the ternary operator (`?:`) and the Elvis operator (`?:`) for concise conditional expressions:
def result = (7 % 2 == 0) ? "7 is even" : "7 is odd"
println result

def nullableValue = null
def nonNullValue = nullableValue ?: "default value"
println nonNullValueThese operators can be useful for simple conditions, but for more complex logic, full `if`/`else` statements are recommended.