dependencies {
    val swaggerVersion = "2.9.2"
    val hikaricpVersion = "3.3.1"
    val typesafeVersion = "1.4.0"
    val kotlinloggingVersion = "1.7.9"
    val modelMapperVersion = "2.3.7"

    subprojects.forEach {

        if( it.name != "common" ) {
            implementation(project(it.path)) {
                dependencies {
                    implementation(project(":common"))
                }
            }
        } else {
            implementation(project(":common"))
        }
    }

    implementation("com.zaxxer:HikariCP:${hikaricpVersion}")
    implementation("org.springframework.boot:spring-boot-starter-web")
    ::::
}

rootProject.name = "gia"
include("common", "internal")

var

full syntax for any property in Kotlin:

var <propertyName>[: <PropertyType>] [= <property_initializer>]
    [<getter>]
    [<setter>]

Initializer, getter, and setter are optional here, but you need to initialize your variable if you don’t want to specify its type. Otherwise, the compiler will warn you.

class User {
    var firstName: String 
    var lastName: String
}

sealed class ParentClass
data class ClassA(fieldInClassType: Int) : ParentClass()
data class ClassB(fieldInClassType: Int) : ParentClass()

private fun <T: ParentClass>foo(data: List<T>,  classType: Class<T>){
    val list = data as classType
    list.sortedBy{it.fieldInClassType}
}

auth.signInWithEmailAndPassword(email, password)
        .addOnCompleteListener(this) { task ->
            if (task.isSuccessful) {
                // Sign in success, update UI with the signed-in user's information
                Log.d(TAG, "signInWithEmail:success")
                val user = auth.currentUser
                updateUI(user)
            } else {
                // If sign in fails, display a message to the user.
                Log.w(TAG, "signInWithEmail:failure", task.exception)
                Toast.makeText(baseContext, "Authentication failed.",
                        Toast.LENGTH_SHORT).show()
                updateUI(null)
                // ...
            }

            // ...

}

pew()

A

b.pew().pew2()

b.apply { pew().pew2() }