data scraping javascript

= 1; returnBar//return 3;}varA = 0;varb =foo (a); console.log (a)//0Console.log (b)//1//if return 3 gets 3//do not add return,functionFoo2 (bar2) {bar2= 1;}vara2 = 0;varB2 =foo2 (a2); console.log (a2)//0Console.log (b2)//undefinedReturn is for returning the function value, it really has no special magical effect.In fact, directly delete the return, try to know if it is, how can I doubt this.wait, Why does the above a not be modified, is it related to a is a number?The problem here should be on t

Analysis of data access performance optimization in javascript and javascript Performance Optimization Generally, writing code considers code readability, scalability, and browser parsing. Reducing the number of Code increases the loading speed of code performance, which is what every coder is pursuing. In javascript,

How can JavaScript display tens of thousands of data records and tens of thousands of javascript records at a time? A colleague told everyone that he saw an interview question on the Internet: "If tens of thousands of data entries are sent to the front-end in the background, how can the front-end be rendered to the pag

This article focuses on the study notes of JavaScript data types. For more information, see five simple data types in ECMAscript, also known as basic data types: undefined, Null, Boolean, Number, and String. There is also a complex data type-Object. Undefined type When var

This article mainly introduces the data structure and algorithm in JavaScript (3): linked list. This article describes the single-chain table and double-chain table, as well as code instances for adding and deleting sections, for more information about the queue and stack in javascript, we can see that the queue and stack are both a special linear table structure

This article mainly introduces how to bind LI List data using JavaScript to bind Li list items to numeric items, this section describes how to bind the LI list data in javascript by referring to the following examples of how to use the JavaScript mouse onmousemove, onmouseou

Learning. Some strange features of JavaScript data types are found: Javascript is a very flexible scripting language. In addition to the well-known weak types and weak definitions, there are also some weird features that are not quite relevant to JavaScript data types: 1.

This article mainly introduces how to convert operations between different types of javascript data. For more information, see converting basic data of different types in javascript, there are rules to find such conversions, and they are not random. In JavaScript, there are

This article mainly introduces the implementation method of the binary search tree in javascript data structure. it analyzes in detail the concept and principle of the binary search tree and the method of implementing the binary search tree in JavaScript, it has some reference value for learning JavaScript

ECMAScript is a dynamic language built on five simple data types (Undefined, Null, Boolean, Number, String) and one complex data type (Object. This article will review simple data types. I will try to describe them from the perspective of Programming Practice. The following code runtime environment is FireFox 14.0.1. Simple