javascript replace()正则替换实现代码

var data = "123123,213,<,12312,>,312,3,cat,dsfsdfs,"; 
alert(func(data)); 
function func(str) 
{ 
var reg = /<|>/g; 
str = str.replace(reg,function($1){ 
if($1=='<'){ 
return '<'; 
}else{ 
return '>'; 
} 
}); 
return str; 
} 
 
很基础...能举一反三最好.