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SEARCH KEYWORD -- Function call

  this in JavaScript

this is a keyword in JavaScript. It refers to an internal object created automatically when a function executes, it can only be used in a function. For example:        function test(){ 　　　　this.x = 1; 　　}The this keyword will change when a function is called in different situations. However, the general rule is : this refers to the object which calls the function.Next we discuss the use of this in 4 different situatio...

   this,keyword,use,JavaScript     2012-05-05 12:47:37

  Understand this in JavaScript

In JavaScript, this is always pointing to the owner of a function or a method. Function Let's check out function first. function introduce() {      alert("Hello, I am Laruence\r\n"); } For this function, what does this point to? In JavaScript, a global function's owner is the current page, i.e, the window object. Because its a method of the window object if we define a global function. Now you should know the this will point to the window object in the above function. ...

   JavaScript,this,event,call     2013-04-03 04:10:03

  JavaScript: Passing by Value or by Reference

In JavaScript, we have functions and we have arguments that we pass into those functions. But how JavaScript handles what you’re passing in is not always clear. When you start getting into object-oriented development, you may find yourself perplexed over why you have access to values sometimes but not other times. When passing in a primitive type variable like a string or a number, the value is passed in by value. This means that any changes to that variable while in the function are com...

   JavaScript,Function,Pass by reference,Pa     2011-07-28 11:05:25

  How does PHP session work?

This article is about how PHP session works internally. Below are the steps : 1. Session in PHP is loaded into PHP core as an extension, we can understand it as an extension. When session extension is loaded, PHP will call core functions to get the session save_handler, i.e interface or functions for reading and writing session data. By default, PHP will handle session data by writing and reading files on the server. But PHP also supplies custom methods for handling session data, we can use sess...

   PHP, session, mechanism     2012-12-28 13:36:49

  this in JavaScript in detail

this in JavaScript is always confusing, it is one of the most frequently seen traps in JavaScript. this is not a good design in JavaScript(You can refer some other design flaws of JavaScript here), since it's lazy binding feature, it can be a global object, the current object or.... Some people even avoid using this in JavaScript. Actually if you master how this works, then you will know how to stay away from these traps. Let's take a look at what this points to in below situations. 1. In global...

   JavaScript,this,bind     2013-05-09 18:35:12

  malloc/free and new/delete in C++

malloc and free are C++/C language standard library functions, while new/delete are operator of C++. They can be used to allocate dynamic memory and free memory in C++ programs malloc/free can not meet the requirements of dynamic objects creation. Object needs to call the constructor to initialize the object when creating, the object needs to call the destructor before it is destroyed  Since malloc() and free() are library functions rather than operators, the compiler has no control permiss...

   C++,memory,malloc,free,new,delete     2012-06-20 06:52:09

  Java API vs Framework

What is the difference between a Java Library and a framework? The two concepts are essentially important for a Java developer. The most important difference between a library and a framework is Inversion of Control. It means that when you call a library you are in control. But with a framework, the control is inverted: the framework calls you. (This is called the Hollywood Principle: Don’t call Us, We’ll call You.) This is pretty much the definition of a framework. Basicall...

   Difference,API,Framework,Library,Java     2011-12-19 13:40:33

  The confusing strtotime() function in PHP

Frequently PHP programmers get confused of the use of i month, -1 month, next month in strtotime() function. and hence it leaves some impression to programmer that this function is not that reliable. Let's take one example of strtotime call with -1 month and see why it leaves this impression. date("Y-m-d",strtotime("-1 month"))  // Assume today is 2018-07-31 What's the output of above call? The answer is 2018-07-01. Why not 2018-06-30? So people get confused. It appears that this is ...

   PHP,STRTOTIME,FIRST DAY OF,-1 MONTH     2018-08-04 05:49:32

  Update parent window after closing the window opened by window.open()

Imagine we have a webpage which has a text field to let user enter a date. Usually, we may create a calendar window to ask the user to pick one date from the calendar window, when the date is picked, the calendar window will close and the date picked will be put into the text field. This way involves the window.open() method in JavaScript, and we may think how the opened window knows its parent window and then updates the parent window. I give a simple demo on this.We have two pages, on is the p...

   window.open, JavaScript,update, return value     2012-06-23 01:36:32

  Three ways to define class in JavaScript

In object oriented programming, class is the template of object, it defines the properties and methods of a group of objects. Unfortunately, JavaScript doesn't support class, but we can have some workarounds to simulate class.1. Constructor functionThis is the classical approach, it is also the approach mentioned in many text books. It uses the constructor function to simulate class and it uses the keyword this to represent the object internally.function Cat() {　　this.name = "Kelly...

   JavaScript,Class,Method,Private,Inheritance     2012-07-09 11:59:51

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