JavaScript Function Basics

1. JavaScript Function Basics

　　1. Defining methods

　　　　　　

2. Methods for calling functions

　　　　

3. Function methods

　Apply: Call the function as an array method to pass the parameter as an array to the method

Call: A method that invokes a function as an object to pass a set parameter to the method

ToString: Returns the string representation of a function

4. Arguments objects

arguments Object

Function: A list of parameters that hold arguments

Attribute: can only be initialized automatically within the function body using a subscript attribute but not an array function declaration

Property:

A) length Gets the lengths of the function arguments

B) callee Returns the function that is currently pointing

C) Caler Returns the name of the function that is calling the currently executing function

5. Function parameters

　　　Parameter type:

Parameters that are used when a parameter definition function receives the parameter passed when the parameter is called

Actual arguments passed to the function when the argument is called

Characteristics:

No limit on the number of parameters

Argument < parameter superfluous parameter = undefined

Argument > Parameter superfluous argument ignored

There is no limit to the data type of the parameter

Accessing a parameter array through a arguments object

Parameters are always passed by value

Basic type pass-through value

Reference type Address

6. Pointer identification

　　　　This points to the current action object

Callee pointer to the function that the parameter collection belongs to

Prototype pointing to the prototype object that came with the function

Constructor points to the constructor that created the object

JavaScript Function Basics