function compare(ar1,ar2){
var ar3=[];
var i,j;
var b=false;
for(var i in ar1){
b=false;
for(var j in ar2){
if(ar1[i].flag==ar2[j].flag){
b=true;
break;
}
}
if(!b){
ar3.push(ar1[i]);
}
}
return ar3;
}
原文：http://www.cnblogs.com/isylar/p/4921369.html