there are :
- the core JavaScript language = minimal API without I/O functions
- client-side JavaScript = hosting environment (browser)
to debug : console.log() or alert()
Chapter 2: Lexical Structure
- Character Set
- support Unicode
- Case Sensitive
- ignores Whitespace
- Comments
// This is a single-line comments.
/* This is also a comment */ // and here is another comment.
/*
* This is yet another comment.
* It has multiple lines
*/- Literal
1.2 // The number one point two
"hello world" // A string of text
'Hi' // Another string
true // A Boolean value
false // The other Boolean value
/javascript/gi // A "regular expression" literal (for pattern
matching)
null // Absence of an object
{ x:1, y:2 } // An object initializer
[ 1, 2, 3, 4 ] // An array initializer