Explain the concepts of immutable and mutable variables in Kotlin.

In Kotlin, variables can be either immutable or mutable.

Immutable Variables: Immutable variables are declared using the val keyword. Once assigned a value, its value cannot be changed or reassigned. They are read-only and provide a guarantee of immutability.
val name = “John” // Immutable variable
name = “Alex” // Error: Cannot reassign value to an immutable variable
In the above example, the name variable is declared as an immutable variable using val. Once assigned the value “John”, it cannot be changed or reassigned to another value.

Mutable Variables: Mutable variables are declared using the var keyword. They can be assigned a value initially and then modified or reassigned later. Mutable variables provide flexibility for value changes during program execution.
var age = 25 // Mutable variable
age = 30 // Value can be modified or reassigned
In the example, the age variable is declared as a mutable variable using var. It is initially assigned the value 25 but can be modified or reassigned to another value, such as 30, later in the program.