Issue #20742 has been updated by jeremyevans0 (Jeremy Evans). Tracker changed from Bug to Feature ruby -v deleted (3.3.4) Backport deleted (3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN) Assigning in post-conditionals is a fairly common in Ruby. If this is to be a warning, it would have to be limited to cases where the variable being assigned in the post-conditional was not in scope before the post-conditional, and is accessed inside the conditional body. ---------------------------------------- Feature #20742: Trying to assign to a variable in statement modifier should emit a warning https://bugs.ruby-lang.org/issues/20742#change-109783 * Author: esad (Esad Hajdarevic) * Status: Open ---------------------------------------- There is an example in Control Expressions documentation: ``` p a if a = 0.zero? # raises NameError “undefined local variable or method ‘a’”. ``` However, if we had already defined `a` there would be no exception raised. If one uses something like `p` for scratch variable, due to Kernel#p, also no exception is raised. Statement modifier is generally somewhat inverting the code flow (the right part is evaluated first then the left part), so it is not really obvious why binding variables shouldn't follow the same flow. A warning would be very beneficial. -- https://bugs.ruby-lang.org/