In general, we consider it does not matter either a line is ended with semicolon or not, but it can cause many issues particularly in case of minification.
this keyword may refer to different things with respect to context. For example, in constructor this refers to object, in simple function this refers to window .
A closure is a function having access to the parent scope, even after the parent function has closed. Closures are very interesting feature and very similar to delegates with persisted state of outer function.
Context and Scope are Different things
Context and Scope are different things, in simple we can say Scope defines accessibility and life span, on other hand Context refers to what and where.