jwalgemoed

// We can explicitly work against interfaces
List<String> list = new ArrayList(); // type: List<String>

// Using var, we can't do this without casting
var list = new ArrayList<String>();  // Inferred type ArrayList<String>
var list = (List)new ArrayList<String>(); // Inferred type List<String>

jwalgemoed

// Classic declaration, we are repeating ourselves
Integer ten = new Integer(10);

// New declaration, using 'var' 
var ten = new Integer(10);

jwalgemoed

// Classic declaration
ArrayList<Integer> list = new ArrayList<Integer>();

// But honestly, since Java 7 Java we can use the diamond operator <> (or omit it entirely)
ArrayList<Integer> list = new ArrayList();

// Var declaration
var list = new ArrayList<Integer>();

jwalgemoed

class SomeClass {
    // Kotlin allows this, as you can specify the intended type here
    var property: String
}