javascript concatenate variables

determined by the search, now the scope of the current level, if not, in the upper scope to find, and so on, so access to local variables is more efficient than accessing global variables. Because there is no need to pick up the chain of scope3. memory-related　　JS also has a garbage collection mechanism, we do not need to worry about memory leaks, garbage collection mechanism will automatically manage the

is actually a pointer to the original variable, and this pointer points to an object stored in the heap. When the copy is complete , the two variables point to the same object in the heap , so changing one of the values will have an effect on the other. Has the following code var obj1 = new Object (); var obj2 = obj1; Obj1.name = "Nicholas"; alert (obj2.name); "Nicholas"　　So the above code executes the process as follows:Third,

the variables in the execution environment are accessed in an orderly manner at different levels of execution, to see the following code:javascript var color = "blue"; function changeColor(){ var anotherColor = "red"; function swapColors(){ var tempColor = anotherColor; anotherColor = color; color = tempColor;Passing parametersIn JavaScript, the arguments are passed in 值类型来传递 , even if you pass in a refere

is actually a pointer to the original variable, and this pointer points to an object stored in the heap. When the copy is complete, the two variables point to the same object in the heap, so changing one of the values will have an effect on the other. Has the following code var New Object (); var obj2 = obj1; = "Nicholas"; alert (obj2.name); // "Nicholas"　　　so the above code executes the process as follows:　　　　　Third, transfer para

Lesson 1 Variables Article Title: Learn JavaScript: Lesson 1: JavaScript VariablesBy Stephen ChapmanTranslator: Hao Xiaoru http://www.haoxiaoru.info/ (This article is long and smelly, but it is extremely easy to understand. It is only suitable for beginners of JavaScript, especially those with no foundation) 1.1 Introd

,arr,obj) { display (num,bool,arr,obj);//num=,bool=true,array=[,,],object.test= num = ; bool = false; arr[] =; Obj.test = ""; Display (num,bool,arr,obj);//num=,bool=false,array=[,,,],object.test= arr = [,,]; obj = {test: ""}; Display (num,bool,arr,obj);//num=,bool=false,array=[,,],object.test= } Test (outer_number,outer_ Boolean,outer_array,outer_object); In the code above we created 4 global variables, the type is numeric, Boolean, Array, objec

The following small series will bring you an article on the improvements in JavaScript variables and function declarations. I think this is quite good. Now I will share it with you and give you a reference. Let's take a look at the phenomenon with xiaobian: 1. In JavaScript, the declaration of variables and functions

I. Basic types and reference types A primitive type value refers to a simple data segment, whereas a reference type value refers to an object that may consist of multiple values. When you assign a value to a variable, the JavaScript parser first determines whether it is a basic type or a reference type, the base data type can manipulate the value stored in the variable directly, and the value of the reference data type is the object that