JS Learning Note 2 (Chapter 5 operation method)

5.2.5 operation

Concat (); slice ();

5.2.7 method of position operation

The others do not repeat

5.5 Functions

1, the function is actually an object, each function is an instance of the functions object, as with other reference types, have properties and methods.

A function name is a pointer to a functional object.

How to create a function:

1. Functions are generally defined by function declaration syntax

function sum (num1,num2) {return num1+num2;}

2. You can also use function expressions to define

var sum=function (num1,num2) {return num1+num2;} There is no need to declare the name of the function, directly use the variable to refer to the function

3. Use function constructor (not recommended)

var sum=new function ("Num1", "num2", "num1+num2");

5.5.2 function declaration and function expression

The parser first adds a function declaration to the execution environment.

JS Learning Note 2 (Chapter 5 operation method)