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Functions

Functions let you organize code into reusable, named blocks.

Defining Functions​

Basic Function​

fun greet() {
    print("Hello!")
}

Function with Parameters​

fun greet_person(name: Text) {
    print("Hello, " + name)
}

Function with Return Value​

fun add(a: Int, b: Int): Int {
    return a + b
}

Expression Body​

For simple functions, you can use an expression body:

fun multiply(a: Int, b: Int): Int = a * b

Calling Functions​

fun main() {
    greet()                    // Call greet()
    greet_person("Alice")      // Call with argument
    let result = add(5, 3)     // Call and store result
    print(result)              // Print: 8
}

Multiple Parameters​

fun calculate_area(length: Float, width: Float): Float {
    return length * width
}

fun main() {
    let area = calculate_area(10.0, 5.0)
    print("Area: " + area)  // Area: 50.0
}

Default Parameters​

fun greet_with_title(name: Text, title: Text = "Mr.") {
    print("Hello, " + title + " " + name)
}

fun main() {
    greet_with_title("Smith")           // Hello, Mr. Smith
    greet_with_title("Jones", "Dr.")   // Hello, Dr. Jones
}

Local Variables​

Functions can have their own local variables:

fun calculate_tax(price: Float): Float {
    let tax_rate = 0.08  // Local variable
    return price * tax_rate
}

What's Next?​