pem scope

Scope : Scope is the accessible scope of variables and functions, that is, scope controls the visibility and life cycle of variables and functions. In JavaScript, the scope of variables has global scope and local

Scope Global scope Local scope Scope chain Execution context Active Object Closed Bag Closure optimization There is a concept in JavaScript that has not been learned before--closures. What is closure? A closed package from a superficial understanding is related to the scope

Python variable ScopeVariable Scope LEGB1. Scope of variablesWhen you create, change, or find a variable name in a Python program, it is done in a space (namespace) that holds the variable name, which we call the scope. The scope of the Python is static, where the variable name is assigned in the source code to determi

a summary of the basic functions of JS including lexical scope and module Foundation. 1 Compiler---scope---engineThe compiler is responsible for parsing and code generation, and the scope is responsible for maintaining a series of queries that consist of all identifiers (variables), and the engine is responsible for executing the code according to the rules defin

Nested functions (Scope chain) When you are nesting a function, be aware that the actual scope chain is changing, which may not seem intuitive. You can put the following code into the Firebug monitoring value changes. Copy Code code as follows: var testvar = ' Window property '; var O1 = {testvar: ' 1 ', fun:function () {alert (' O1: ' +this.testvar+ ' var O2 = {testvar: ' 2 ', fun:functio

Copy Code code as follows: /* Code 1 * * var scope = "global"; function Checkscope () { var scope = "local"; function Childcheck () { var scope = "Childlocal"; document.write (scope); } function childundefined () { document.write (scope); var

http://www.cnblogs.com/wolf-lifeng/p/3156936.html2.3 Global Scope 2.3.1 OverviewThe global scope is the largest namespace scope, unlike the user-defined namespace scope, where the global scope does not need to be defined, and it naturally exists in C + + programs. The global

The scope and context (contexts) in JavaScript are unique to the language, thanks in part to the flexibility they bring. Each function has a different context and scope of variables. These concepts are backed by some powerful design patterns in JavaScript. However, this also brings a lot of confusion to the developers. The following is a complete revelation of the context and

Original article: http://blogs.msdn.com/ B /jscript/archive/2007/07/26/scope-chain-of-jscript-functions.aspx In JavaScript, the function scope chain is hard to understand. this is because the scope chain of functions in JavaScript is far from that in other languages such as C and C ++. this article explains in detail the knowledge related to function

This article describes the scope rules in Python, including local scope, global scope, built-in scope, and nested scope, you can refer to Python as a static scope language, although it is a dynamic language. That is to say, in Pyt

The project scope management knowledge field contains six Process Groups, including planning project scope management, collecting requirements, defining scope, creating WBS, determining scope and control scope, this article will introduce the main content of project

The example of this article analyzes the use of JavaScript scoped chain (scope Chain). Share to everyone for your reference, specific as follows: About the scope of JS chain, has been heard, and have seen several introductory blog, but has always understood the ambiguity. Recently and carefully looked at the "Understanding through JavaScript" This book, feel too Deep, in the "Code of Time and Space" sectio

Before writing a JavaScript closure is what the article understanding closure, feel written very clearly, you can simply understand the cause of closure, but see comments are said to understand the scope chain and active objects to really understand the closure, initially dismissed, Later, when interacting with colleagues in the company, I found that the scope and execution environment was really important

The variable scope is the region in the program that defines this variable. First, paste a piece of code. If you are not confused about the output of the code, you do not need to read it below. The Code is as follows: /* Code 1 */Var scope = "global ";Function checkScope (){Var scope = "local ";Function childCheck (){Var s