Nil and nil - difference
12323
iPhone : Difference between nil vs Nil and true vs TRUE
145038
What is different between "for" and "to"?
48026
What's the difference between X = X++; vs X++;?
129148
How can I memoize a method that may return true, false, or nil in Ruby?
73299
What is the difference between '->' (arrow operator) and '.' (dot operator) in Objective-C?
151825
Is there any difference between "foo is None" and "foo == None"?
52623
Variable declaration difference in Objective-C
65694
What is the difference between NULL, '\0' and 0?
18042
What is the difference between `let` and `var` in swift?
10138
How to avoid NoMethodError for missing elements in nested hashes, without repeated nil checks?
68676
Testing for nil in Objective-C -- if(x != nil) vs if(x)
25871
Difference between "while" and "whilst"
131841
Difference of closures and closure of difference
102641
ObjectiveC: if (obj) {...} AND if (obj != nil) {...}, which is better?
129142
What is the difference between an indeterminate and variable?
1784
What's the difference between passing by reference vs. passing by value?
9988
What is the difference between  in ERB in Rails?