Misc #15265
Updated by CaryInVictoria (Cary Swoveland) about 6 years ago
The v2.5.1 documentation for this method states, in part, "Sets the instance variable named by symbol to the given object, thereby frustrating the efforts of the class's author to attempt to provide proper encapsulation." The phrase beginning, "thereby..." is not necessarily true and seems to mock the fact that the method has been provided to us for its use. Suppose, for example, that that author has provided getters and setters for *all* of an object's instance variables, so there is no encapsulation issue. There still may be situations where this method (and `Object#instance_variable_get`) could be used to advantage. One is where we want to perform certain operations on all instances variables. Where it is possible to write, For that we might write: `<instance>.instance_variables.each { |v| f(v) }`, this }`. This has several advantages over manipulating the instance variables individually: it requires less code, debugging and testing is simpler, there is less chance of introducing a bug; and adding, removing or renaming instance variables may not require `f(v)` to be changed.