Android Development with Kotlin

Using the apply function for initialization

Sometimes we need to create and initialize an object by calling some methods or modifying some properties, such as when we are creating a Button:

    val button = Button(context) 
    button.text = "Click me"   
    button.isVisible = true 
    button.setOnClickListener { /* ... */ } 
    this.button = button 

We can reduce code verbosity by using the apply extension function. We can call all these methods from the context where button is the receiver object:

    button = Button(context).apply { 
        text = "Click me" 
        isVisible = true 
        setOnClickListener { /* ... */ } 
    }