JavaScript missing makeup

Heap Value Type
Primitive type)
Undefined: undefined (case sensitive: type/value, the same below)
Null: null (Undefined derived from Null)
Boolen: true/false
Number: Number. MAX_VALUE/Number. MIN_VALUE/NaN; isNaN () function (Note: The new version has changed and is awaiting query)
String:
Type conversion:
Boolen ()/Number ()/String () ** indicates the type name.
ToString (): toString (2/8/16)
IntParse ()/floatParse ():


Stack reference type
Predefined
Object:
Boolen:
Number: toFixed ()
String: (omitted)
Instanceof ()


Operator
Delete
Void <a href = "javascript: void (window. open ('about: blank ')"> Click me </a>

Label:

Object:
An object is an unordered (different from an array) set of name-value pairs (attributes and methods ).
Create: new and {}
Extension: Add new attributes to the object (meaning modifying the instance at runtime !) Operator: "." or "[]"
Constructor: can judge the type, but unlike typeof, an object is returned.
Prototype: Object Structure

Attribute: (variable)
Scope
Var: local variable, that is, the variable scope is the innermost function body.

Method: (function)
JavaScript supports the First-Class function, which processes the function as an object. Therefore, it can be assigned to a variable (=), stored as an array element, and treated as a return value.

This:
Simple memory:
Global functions (simple declared functions on the page): window
DOM event handler (a function used to process a DOM Event): DOM elements associated with the event (note event bubbling)
Constructor: The instance itself

Understanding:
In general, this always points to the object that calls the function (the so-called "RunTime confirmation ")
Special case: apply () and call (). this points to the parameter objects of the above two functions.

Closure:
Form:
Function defined in a function

Function:
Ability to read internal variables of other functions
Connect the function to the function.
Keep the values of these variables in the memory.

Array:
An ordered (different from an object) value set. These values can be of different types.

Create: new Array () or []