Kotlin Functions

A function is a reusable block of instructions designed to perform a specific job. You define it once and call it when needed.

Use the keyword fun, followed by a name, optional input values (parameters), and the action it performs.

This function prints a message.

Call it like this: greet()

You can pass data into a function by using parameters:

fun sayHello(name: String) {     
     println("Hello, $name!") 
}

Call it with a name: sayHello("Sahand")

At times, you need a function to return a result after finishing its task.

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

Use it like:

val result = add(4, 5) 
Println(result)  // Outputs: 9

For simple tasks, Kotlin allows short syntax:

fun square(n: Int) = n * n

Functions can use default values:

fun greetUser(name: String = "Guest") {     
     println("Hi, $name!") 
}

Call:

You can mention parameter names while calling:

fun displayInfo(name: String, age: Int) {     
      println("$name is $age years old.") 
}  

DisplayInfo(age = 25, name = "Sahand")

Watch these YouTube tutorials to understand KOTLIN Tutorial visually:

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