javascript concatenate variables

"]: "";// Determine which function to call based on the value returnedSwitch (strFunName){Case "enter ()":Enter (); // call this functionBreak;Case "Others ":// Call other functionsBreak;Default:// Call the default FunctionBreak;}}}Public void enter (){//...... For example, calculating a value}2. How to access the C # variable in JavaScript?The answer is as follows:Method 1: 1. Access the Method 2: 1. For example, public string n is defined in the bac

First, the concept1. Variable declarationIn JavaScript, variables are generally declared by means of the var keyword (except the implicit declaration, the Let keyword Declaration), which declares a,b,c three variables (and assigns a value to a) by using the var keyword:var a=1,b,c; Keyword explicitly declares a variable a,b,c and assigns a valu

pre-declare all the variables you want to use.The code snippet above performs the following behavior as follows:var"global";(function() { var myname; alert(myname); "local"; alert(myname);})();Forget the side effects of VarBecause of the two characteristics of JavaScript, it is surprisingly easy to create global variables unconsciously. First, you ca

First, JavaScript introductionJavaScript is a literal translation (which preserves both the original and the original) scripting language, a dynamic type, a weak type, a prototype-based language, and a built-in support type. Its interpreter is the JavaScript engine, which is part of the browser and is widely used in the client's scripting language. In the area of Web site development for interaction with us

function to rely on the global variable. At the same time, the portability of the function is reduced.(3) Global variables make the code readability of the function less readable. Because multiple functions may use global variables, the values of global variables may change at any time when the function is executed, which is detrimental to the troubleshooting an

sentence in JQuery1.5Window.jquery = window.$ = jQuery;Advantages of Global Variables:You can reduce the number of variables and reduce the time consumption caused by data transfer of actual parameters and formal Parameters.Disadvantages of global Variables:(1) the global variable is stored in a static storage area, which allocates memory for the program to run, and the program ends releasing the Memory. C

Values for base types and reference types　　Basic type (simple data segment)The base data type is accessed by value, because the actual value is stored in the variable.　　Reference types (objects that may consist of multiple values)Reference types are objects that are held in memory, and JavaScript does not allow direct access to locations in memory. So it's actually manipulating the object's reference rather than the actual object.1. Dynamic Properties

1. Javascript variable type Javascript variables are classified into basic types and reference types. the basic data type is a simple data segment that directly has a stack space. This type directly stores the value at a location in the memory. the referenced data type stores the addresses of objects actually stored in the heap memory. There are five basic data t

Avascript can be said to be the most widely used language today, although the client browser script, but the use of JavaScript can do a lot of unexpected effects, due to the good and bad programmers, there will be inevitable redundant code. Avoid creating extra variables and code in JavaScript In general, I hate programming code to generate redundant

Phenomenon:1. The Declaration of variables and functions in JavaScript is promoted to the top of the execution.2. The promotion of the function is higher than the variable.3. Inside the function if you declare an external variable of the same name with Var, the function will no longer look up.4. Anonymous functions are not promoted.5. The functions in different Example:function declaration promotion above V

JavaScript Release variablesIn JavaScript, you can use "delete" To manually delete variables, in such a way that the GC (garbage collection) to reclaim memory, but in JS, not all the variables can be deleted.1, the Var declaration of the global variable "a" after the use of "delete a" after the output value is still "1

through a Array() function:New // array created [1, 2, 3]However, for the sake of readability of the code, it is strongly recommended to use it directly [] .The elements of an array can be accessed through an index. Notice that the starting value of the index is 0 :var NULL true ];arr[// Returns an element with an index of 0, or 1// Returns an element with an index of 5, which is true// Index is out of range, return undefinedObjectA JavaScript obj

Original: Learn JavaScript from the beginning (eight)--variablesFirst, the variable classification:Base type value: null, Undefined, number, string, Boolean;Reference type value: Keep an in-memory object, such as: Object/array/function/date/regexp/error/map/set ...Second, the attributeThe two are defined in a similar way: Create a variable and assign it a value.2.1 Base Type value cannot add delete attribute2.2 Properties of a reference type can be dy

Variables in JavaScript are declared by the VAR keyword (variable). Copy Code code as follows: var school = "Beijingyizhong" You can also give variables multiple values by using the var keyword. Copy Code code as follows: var school = "Beijingyizhong", diqu = "Beijing", age = 100; In addition, unlike Java,

variables, scopes, and memory issues There are two types of execution environment-Global and local The scope chain is longer, there are two cases: the catch block of the Try-catch statement, the WITH statement. JavaScript does not have block-level scopes, which are variables in the if,for loop, and are not destroyed after the block has ended.

in JS, there's no block-level scope.Give two examples:If statement block:if (true) {var name= ' Ling ';} alert (name);Output: LingFor statement block; for (Var i=0;iOutput: 10Output: LingThis means that the final result is a global variable under window: in the function body of JavaScript, there are a few things to note:1, there is no VarIf there is Var, declaring the variable inside the function is a local variable, as in the following example, the

i = 0; i This approach appears to be the safest specification, and many students who go from C and Java to front-end development prefer this, in fact, perhaps due to a misunderstanding of an important concept in JavaScript--a variable scope. Unlike C and Java,javascript, there is no real block scope, that is, after the end of the first loop, Console.log (i) does not print undefined or throw reference