If a local variable is never reassigned, it should be declared val to make it a constant within its scope. This makes the code easier
to read and protects the variable from accidental re-assignments in future code changes.
What is the potential impact?
Readability and Understanding
If a variable is declared val, it is evident to readers that the variable value is never altered but serves as a constant. This makes
it easier to understand the code because readers do not need to keep track of possible state changes of the variable.
Wrong code
Developers might intend for a variable to remain unchanged and have their code relying on that constraint. For example, a variable could be
expected to have a specific range. Changing the value of the variable could break that constraint. Also, developers could have assigned the wrong
variable. If the developers inject a value into a variable with an annotation, they should declare it as late initialized.
Declare variables that remain unchanged as val to avoid these mistakes.
