対象に向けたjavascript(メモ)

 
  
//         
  
var items = new Array('1','2','3'); 
  
//           
  
var itemRef = items; 
  
items.push('4'); 
  
//items   itemRef       
  
alert(items.length === itemRef.length); 
  
 
  
//              
  
var item = 'test'; 
  
var itemRef = item; 
  
item+='ing'; 
  
//  item itemRef          
  
alert(item != itemRef); 
  
 
 

 
  
//arguments              
  
function sendMessage(msg,obj){ 
  
if(arguments.length ==2) 
  
obj.handleMsg(msg); 
  
else 
  
alert(msg); 
  
} 
  
 
 

 
  
//typeof                
  
//      num   string    
  
if(typeof num == 'string') 
  
//  typeof   object array       
  
 
  
//  constructor   num   String   
  
if(num.constructor == String) 
  
if(num.constructor == Array) 
  
 
  
//                     
  
function strict(types,args){ 
  
if(types.length != args.length){ 
  
throw "      "; 
  
} 
  
for(var i=0; iif(args[i].constructor != types[i]){ 
  
throw '       ' 
  
} 
  
} 
  
}