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Two binding keywords:

• val — immutable binding (like final in Java, const in JS). Idiomatic Scala uses val everywhere possible.
• var — mutable. Avoid unless you really need mutation.

val name = "Ada"        // type inferred as String
val age: Int = 36       // explicit type annotation
var counter = 0         // mutable
counter += 1

Scala is statically typed but with strong inference. You almost never need to write types except on function parameters.

Common types:

• Int, Long, Short, Byte — integers
• Double, Float — floats
• Boolean — true/false
• Char, String — text
• Unit — like void (no meaningful value)
• Any — top type (everything is an Any)

Read a line: scala.io.StdIn.readLine(). Parse: "42".toInt, "3.14".toDouble.