javascript definitive guide 8th edition pdf

StatementAn expression is a phrase in JavaScript, and the statement is a JavaScript whole sentence or command. Use a period to end to separate statements. An expression evaluates a value, but the statement is used to execute to make something happen.5.2 Compound statements and empty statementsCompound statement: Enclose multiple statements in curly braces to form a conforming statement.{ x = Math.PI; CX =

() method to modify the array, but invalid for the string!! Five. Functions1. A function that initializes an object becomes a constructor (constructor).2. There are two ways of defining a function: A. Define statement b. expression3. Example 1: Traversing object property names and propertiesvar object = {' A ': ' 3 ', ' str ': ' Hello ', ' funcion ': ' fn ', ' B ': ' 0.618 '};function Printprops (obj) {for (var p in obj) Console.log (p + ":" + obj[p] + "\ n")};Printprops (object); //A:3Str:hell

1.To avoid such circular reference problems, it is best to manually break the connection between the native JS object and the DOM element when you do not use them:Code:myobject.element = NULL;ELEMENT.O = null;2. Isfinite (); is a finite number3. Lenin's understanding of the logical approach: A. Hold and study all aspects , contacts and intermediaries of things. Observe things in the development, movement, and change of things. C. Define all human practices into the "definition" of thing

I. Constructor call (with or without return)1. var obj = new Object ();var obj = new Object;The two lines of code are equivalent; expression: New obj.m ();, this is not obj!! The constructor is usually not used with the return keyword;Two. Indirect calls1. Call (), and apply (); Function: Any object can call any method/Call ();--use its own arguments as arguments to the function;Apply ();--to pass in an argument as an array;2. Optional parameter: var a = a | | [];3. Variable-length arguments: A

One. Check whether it is a function.function Isfunction (x) {return Object.prototype.toString.call (x) = = = "[Object Function]";};function square (n) {return n*n;};Alert (isfunction (square)); trueI. Functional programming1. Working with arrays using functionsFor example:function fn () {//some code ...}; Elemnets.reduce (FN);2. Higher-order functions--functions of operation functionsFor example:Function not (f) {return function () {var result = f.apply (this,arguments);Return!result}};var even

1. function as a namespace. form: var Somefn = (function () {var a = 0;return function f () {//...};} ());2. closures. Parameters of an external function cannot be accessed directly within a closure unless the external argument is stored as a variable. For example: var outerarguments = arguments;3. Properties, methods, constructors of functionsA.Arguments.length; (expected number of arguments passed in)Arguments.callee.lenth; (number of actual arguments passed in)B. Prototype propertiesConstruct

1./* ********************************** We can usually add methods to the prototype of a class, in this case: * To achieve the purpose of the extension, now to prohibit this extension. Only * required object.preventextentions (); ***********************************/function () { //to do// Invalid2.Object.seal (); // property cannot be deleted, but can be written and modified Object.seal (Object.prototype); Object.seal (Object.freeze);3. Set the properties of the object to read-only:

removed from the array, and if the second argument is omitted, all elements are deleted from the starting point to the end of the array. Splice () returns an array of deleted elements that return an empty array if no elements are deleted.var a=[1,2,3,4,5,6,7,8];a.splice (4); // return [5,6,7,8],a to [1,2,3,4] // return [2,3],a to [1,4] // return [4],a to [1]Splice () The first two parameters specify the array elements that need to be deleted, followed by any parameters that specify the eleme