Madusudanan

public class RuntimeJavaErrorDemo {
    public static void main(String[] args) {
        String test = null;
        System.out.println(test.length());
    }
}

Madusudanan

class Test {
  var x = None
  println(x.length)
}

Madusudanan

class Person {
  var age = -1
  var name = "Unnamed"
}

Madusudanan

 def factorial(a:Int): Int = {
    if(a <=1) 1 else a * factorial(a-1)
  }

Madusudanan

let factorial 0 = 1; factorial n = n * factorial (n - 1)

Madusudanan

def factorial(a: Int) = {
    if (a <= 1) 1 else a * factorial(a - 1)
}

Madusudanan

val x = 20
//print to the console
//legit, gets inferred as an integer

println(x+10)

//Something stupid as below will throw compile time error
val z = 40
println(z * "justastring")

Madusudanan

val t = 69
//Prints 'E' the ASCII value of E is 69
println(t.toChar)

val s = "Hello World"  
//Just like String char at, prints l
//Trace leads to the same String class charAt method
println(s.charAt(2))

Madusudanan

final ArrayList<Integer> arrList = new ArrayList<Integer>();
//This does not result in error, we are mutating the object itself
//If it were mutable it would result in error to something like it cannot be changed
arrList.add(20);
//This results in error as we are modifying the reference and not the object itself
arrList = null;

Madusudanan

class HelloWorld {
  def main(args : Array[String]){
    println("Hello world")
  }
}