《js学习笔记》word版

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1、JS学习笔记一：CreatingModulesandNamespaces。//thefirstruleofJavaScriptmodules:amoduleshouldneveraddmorethanasinglesymboltotheglobalnamespace.//Createanemptyobjectasournamespace//ThissingleglobalsymbolwillholdallofourothersymbolsvarClass={};//DefinefunctionswithinthenamespaceClass.de

2、fine=function(data){/*codegoeshere*/}Class.provides=function(o,c){/*codegoeshere*/}Inthecaseoftheclassmodule,youcanputthecodeinafilenamedClass.jsandbeginthatfilewithacommentthatlookslikethis:/***Class.js:Amoduleofutilityfunctionsforworkingwithclasses.**Thismoduledefinesasingl

3、eglobalsymbolnamed"Class".*Classreferstoanamespaceobject,andallutilityfunctions*arestoredaspropertiesofthisnamespace.**/Example10-1.Creatinganamespacebasedonadomainname//Createtheglobalsymbol"com"ifitdoesn'texist//Throwanerrorifitdoesexistbutisnotanobjectvarcom;if(!com)com={}

4、;elseif(typeofcom!="object")thrownewError("comalreadyexistsandisnotanobject");//Repeatthecreationandtype-checkingcodeforthenextlevelif(!com.davidflanagan)com.davidflanagan={}elseif(typeofcom.davidflanagan!="object")thrownewError("com.davidflanaganalreadyexistsandisnotanobject

5、");//Throwanerrorifcom.davidflanagan.Classalreadyexistsif(com.davidflanagan.Class)thrownewError("com.davidflanagan.Classalreadyexists");//Otherwise,createandpopulatethenamespacewithonebigobjectliteralcom.davidflanagan.Class={define:function(data){/*codehere*/},provides:functi

6、on(o,c){/*codehere*/}};varcom;//Declareglobalsymbolbeforetestingforitspresenceif(!com

7、

8、!com.davidflanagan

9、

10、!com.davidflanagan.Class)thrownewError("com/davidflanagan/Class.jshasnotbeenloaded");/***com/davidflanagan/Shapes.js:amoduleofclassesrepresentingshapes**Thismoduledefine

11、sclasseswithinthecom.davidflanagan.shapesnamespace*Thismodulerequiresthecom/davidflanagan/Class.jsmodule**///First,checkfortheClassmodulevarcom;//Declareglobalsymbolbeforetestingforitspresenceif(!com

12、

13、!com.davidflanagan

14、

15、!com.davidflanagan.Class)thrownewError("com/davidflanag

16、an/Class.jshasnotbeenloaded");//Importasymbolfromthatmodulevardefine