javascript optional arguments

this series as effective JavaScript 's reading notes. arguments object is just an array-like object, but it does not have the methods provided by the array object, such as Shift , Push and so on. So calls such as:arguments.shift (),arguments.push () are wrong. in the Item and the Item , you know that a function object exists on the Pager and the Apply method, then it is not possible to use them to make

What is argumentsarguments It's a built-in object in JavaScript, it's weird and often overlooked, but it's really important. All major JS libraries take advantage of the arguments object. So agruments objects are necessary for JavaScript programmers to be familiar with. All functions have a arguments object of their

This article mainly introduces how to reuse javascript by using apply and arguments. If you need it, you can refer to it. First, there is a singleton object, which involves many static tool methods. One of them is each, which is used to traverse arrays or objects. The Code is as follows: Var nativeForEach = []. forEachVar nativeMap = []. mapVar util = {Each: function (obj, iterator, context ){If (obj = n

Returns the function object being executed, which is the body of the specified function object. [function.] Arguments.callee The optional function parameter is the name of the function object that is currently executing. Description: The initial value of the Callee property is the Function object that is being executed. The Callee property is a member of a arguments object that represents a reference to th

following code: function tansto (lat, LNG) // go to the specified location with two parameters, latitude and longitude { map.panto (New GLatLng (lat, LNG )); Google Maps api , jump to the coordinates at the specified place return a double The value of the type is given to varresult } Attention:(1) the panto () function in JavaScript above is a function in the Google Map API that can customize the relevant function accordi

function Add2 () {for (var v in arguments) {// V is the parameter index, starting from 0. log (arguments [v]) ;}} Add2 (3, 4); // output 3 4add2 (3, 4, 5); // output 3, 4 5 The above shows that there are no strict restrictions on JavaScript function parameters. For function add (a, B), A and B only identify the function with two parameters, and the code is reada

1. In JavaScript, the arguments object is a more specific object, which is actually a built-in property of the current function. Arguments is very similar to an array, but is not actually an array instance. Can be confirmed by the following code (of course, in the function Funcarg, the call arguments is not necessarily

I. Briefly introduce JavaScript arguments The arguments object in Javascript is the object created during function execution. Through this function, we can dynamically obtain parameters. If you have learned Java, you may know that the method parameter type can be: type... parameter name, for example: Class test {public

1 Script > 2 Function Test (A, B, C) 3 {4//Todo something white a, B, c5} 6 VaR X = 10 ; 7 VaR Y = "" ; 8 Test (x, y ); 9 / SCRIPT> The test (a, B, c) method has three parameters, but only two parameters are passed during the call. How to determine whether the parameter C exists in the test methodI wrote this in test, and an error is returned. /**If (C = "undefiend "){Alert ("parameter missing "); }*/ the corre

Before you mention the above concepts, first of all, let's talk about the implied parameters of functions in javascript: arguments Arguments The object represents the function being executed and the arguments of the function that called it. [function.] Arguments[n] Parame

1. preface what is arguments, caller, callee? What is the role of javascript? This article will give a basic introduction to this. 2. argumentsarguments: During function calling, a hidden pair named arguments is automatically generated inside the function... SyntaxHighlighte 1. preface what are arguments, caller and ca

1. In JavaScript, the arguments object is a more specific object, which is actually a built-in property of the current function. Arguments is very similar to an array, but is not actually an array instance. Can be confirmed by the following code (of course, in the function Funcarg, the call arguments is not necessarily

] = 100; Console.log (ARG3); //undefined//is still undefined, modified invalid} fn1 ();The opposite: the value of the corresponding arguments can also be modified by formal parameters. The premise is also that the value of arguments is not a special value undefinedfunctionfn2 (ARG1,ARG2,ARG3) {//Arguments[0] value is present, and the value of

Each Javascript function can access a special variable-arguments within its scope. This variable contains a list of all the arguments passed to the function.The arguments object is not an array. Although syntactically it has the same place as an array, for example, it has the length property. But it is not inherited fr

Copy Code code as follows: Copy Code code as follows: 1. In JavaScript, the arguments object is a very special object and is actually a built-in property of the current function. Arguments is very similar to array, but is not actually an array instance. Can be confirmed by the following code (of course, in fact, in t

Research on javascript arguments objects -- Research on jquery source code External plug-ins: $. Fn. tinytip = function (text, customOptions ){Debugger;If (text typeof text === 'object '){CustomOptions = text;Text = customOptions. tooltip;}Var options = $. extend ({}, tooltip_options, customOptions );Options. tooltip = text;If (typeof options. tooltip === 'object '){Options. content = options. tooltip;Opti

The arguments parameter is a collection of all the explicit arguments that are passed to the function when the function is called. It is passed to the inside of the function in an implicit way.This arguments object is an array-like collection of parameters that have length and can be indexed to take a single parameter, and it is not a true array because it cannot

Today we go on to the next article to continue the topic of JavaScript functions. What we're going to talk about today is the--arguments of a function to an important attribute in the image. Related reading: JavaScript function 1--Overview JavaScript function 2--

What is arguments? ArgumentsIt is a built-in object in Javascript. It is odd and often ignored, but it is actually very important. All major JS function libraries use the arguments object. Therefore, the agruments object isProgramPersonnel must be familiar with it. All functions have their own arguments object, which

In JavaScript Functions, the identifier arguments has a special meaning. It is a special attribute of the called object and is used to reference the arguments object. The arugments object is like an array. Note that it is just like it is not. In JavaScript Functions, arguments