function sym(args) {
var arr = [];
var answer = [];
arr = Array.prototype.slice.call(arguments);
answer = arr.reduce(function(a,b){ //合并数组
return a.concat(b).filter(function(item,index,arr){ //过滤两个数组都有的项
return a.indexOf(item) ===-1||b.indexOf(item)===-1;
}).filter(function(item,index,arr){ //数组去重
return arr.indexOf(item) ===index;
});
});
return answer;
}
