Kotlin initialize member variables in constructor

Main.kt

class UsingPrimaryConstructorAndInit(val constructor_parameter: String) {
    private val initialized_by_class: String
    
    init {
        this.initialized_by_class = "asdasd"
    }
}

class UsingSecondaryConstructor {
    private val constructor_parameter: String
    private val initialized_by_class: String

    constructor(param:String) {
        this.constructor_parameter = param
        this.initialized_by_class = "asdasd"
    }
}