Block ↔ Source Code Encapsulate in { } curly braces (excl Object Literals) to define boundary of Lexical Environment

aka Blocks, Code-Block, Code-Blocks, Block-of-code

!recall if & loop statements are inside a block

{ const isPrivate = true }

true. can not read from outside; const block-scoped

{ var notPrivate = true }

true. readable outside Block since var is Function Scoped

References

1. Global Scope ↔ Outside any Block. Variableaccess everywhere

2. function ↔ callable Block of code to perform action or return Value

3. Block Scope ↔ Variable Lookup restrict to inside of Block

4. { var notPrivate = true } ↔ true. readable outside Block since var is Function Scoped

5. Loop ↔ Control Flow to repeat Block Execution

6. if ↔ Control Flow JS Keyword to optionally execute Block on Boolean Context of expression

7. Top-Level Code ↔ Code in Global Scope, outside Block