== Why is this an issue?

Variables that are never updated will always return their default values and so they should be explicitly declared as constant. A ``++let++``-declaration guarantees and clearly signals to the programmer that its value is supposed to and will never change.

This rule applies to non-constant fields and variables which are not set within the codebase.

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== Implementation Specification
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=== Message

Declare variable "{0}" with "let".


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== Comments And Links
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=== on 15 May 2015, 11:57:27 Elena Vilchik wrote:
Consider only "set and read but never updated" variables and not "unused" one.

=== on 8 Oct 2014, 07:20:32 Nicolas Peru wrote:
\[~ann.campbell.2]Why non-private ?

=== on 8 Oct 2014, 12:16:15 Ann Campbell wrote:
\[~nicolas.peru] we already have a separate rule about private fields: RSPEC-1068, and because the advice is different. If they're private and not used, they're dead code. If they're not private and _apparently_ unused, they might still be accessed directly by classes that just aren't currently 'visible'.

=== on 10 Oct 2014, 14:15:18 Freddy Mallet wrote:
@Ann :

* I would use the label "pitfall"
* Moreover for me there is no intersection between this rule and rule RSPEC-1068. In case of RSPEC-1068 we're looking for unused fields whereas here we're looking for fields that ARE really used but never updated and so which should be declared as 'final'
* I would decrease the remediation cost to 2 min and associate this rule to the Maintainability > Understandability characteristic
* This rule would be limited at first to private fields but I would not mention this limitation

=== on 15 May 2015, 09:53:17 Elena Vilchik wrote:
\[~ann.campbell.2] I want to expand the scope of this rule for Swift "Fields *and variables* that are never updated should be constant". WDYT can I do it in subtask for this rule? 

=== on 15 May 2015, 11:52:30 Ann Campbell wrote:
Fine with me [~elena.vilchik]


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