《cocos2d-js教学》javascript_quicksta

1、JAVASCRIPT QUICKSTARTJIANYUN BAO,SENIOR TECHNICAL EVANGELIST, CHUKONGTHE TECHNOLOGY OF MOBILE GAME DEVELOPMENTWhat is JavaScript ?WHAT IS JAVASCRIPT http:/ IS JAVASCRIPT WHAT IS JAVASCRIPT a cross-platform, object-oriented scripting language01inside a host environment (eg. a web browser)03variable d

2、ata types are not declared (dynamic typing)02Why is JavaScript？WHY IS JAVASCRIPT Functional Programming01Simpler code, rapider development 02Close to natural language, easy to understand03Code management easier04Concurrent programming easier 05Code hot updatehttphttpWHY IS JAVASCRIPT Fullstack javas

3、cript framework for web application developmentWHY IS JAVASCRIPT httpJavaScript basic knowledgeDATA TYPE AND VARIABLESDEFINITIONExplicit use var for assignmentImplicit direct assignmentDATA TYPE AND VARIABLESTYPE CONVERSION subtraction (string number) + addition string joint / numbertoString() boole

4、an / number stringDATA TYPE AND VARIABLESTYPE CONVERSIONparseInt() string integerparseFloat() string float non number string NaNDATA TYPE AND VARIABLESVARIABLEScoverage Local override GlobalBASIC DATA TYPEnumber integer / floatboolean true / falsestring must use or “”undefined created but not initia

5、lized variablesnull variables have not dataCOMPOUND TYPESObject object-orientedArray or OBJECTS or new Array()Functiondefinition function functionName(param, ) call functionName(param, );typeof check data typeCOMPOUND TYPESOPERATOR!= / = check value!= / = check value and data type5 = “5” is true (Au

6、tomatic type conversion)null = undefined is true null = undefined is false , (comma) allow Expression place togerther, finally return the rightest value finally a s value is 13OPERATORinstanceof check the variable whether a instance of some data type refer to typeofOPERATORblocks need but dont need

7、; finallySTATEMENTtry catch exception catchingSTATEMENTwith avoid writing object repeatlySTATEMENTIf else if else two branchesFLOW CONTROLBRANCHswitch multi-brancheswhile / do while loop by expressionFLOW CONTROLLOOPfor loop in sectionFLOW CONTROLLOOPendless loop for in kind of foreach loop FLOW CON

8、TROLLOOPtraverse all elements in the array traverse all attributes of JavaScript object continue stop current loop FLOW CONTROLLOOPbreak stop whole loop stop external loop (name: looper) FUNCTIONDEFINITIONNotice do not need declare return type do not need declare parameter type name function FUNCTIO

9、NDEFINITIONanonymous function FUNCTIONDEFINITIONFunction class anonymous function FUNCTIONDEFINITIONthe number of parameters in constructor is unlimited allow a series of string parameters, and the last one is the executive of the function, the statements are separated by “;” (semicolon)Function cla

10、ss anonymous function FUNCTIONDEFINITIONwhen define a function in JavaScript FUNCTIONFUNCTION, OBJECT, METHOD AND CLASSfunction directly call like Java method object also create a object (Function) method append some object as method class also get a Class, has the same name of the functionFUNCTIONC

11、ALLdirect call usually get the last return value non return, get null use new call return this JavaScript objectFUNCTIONTHISthis instance attribute FUNCTIONATTRIBUTElocal variable use var or not declare variable in the functioninstance attribute this prefixclass attribute function name prefixFUNCTIO

12、NCALL METHODdirect call method xxx.foo(para);use call() dynamically call with all parametersuse apply() dynamically call with arguments (array)PARAMETERTYPEempty parameter input as undefined“Duck Type” check type, attribute, method first USE OBJECTOBJECT-ORIENTEDnotice the definition of function doe

13、s not support inheritance syntax inheritance mechanism is not perfectUSE OBJECTOBJECT AND LINKED DATAnotice the object of JavaScript is linked data like Map in Java, “key-value” USE OBJECTINHERITANCE AND PROTOTYPEnotice use “prototype” as pseudo inheritancemechanismevery class has prototype attributewhen extend function and attribute to prototype, as extend the originalclassCocos2d-JS v2.x use thisCREATE OBJECTuse new create CREATE OBJECTuse object create create null object, add function and attribute CREATE OBJECTuse JSON synta