Problem Statement

Most languages provide a way to concatenate two string values, but some languages also provide a convenient way to append in-place to an existing string variable without referring to the variable twice.

Create a string variable equal to any text value. Append the string variable with another string literal in the most idiomatic way, without double reference if your language supports it. Show the contents of the variable after the append operation.

Let's start with the solution:

main =>
  S = "a string",
  S := S + " that is longer",
  println(S).