functiondiff(a,b){
varret=Object.assign({},a,b);
for(varkeyinret){
if(keyina&&keyinb)deleteret[key];
}
returnret;
}
console.log(diff(A,B));
                            

constpickDiffAttr=(obj1,obj2)=>Object.keys(obj2).reduce((ret,attr)=>{
if(ret[attr])deleteret[attr]
elseret[attr]=obj2[attr]
returnret
},{...obj1})
consta={a:1,b:2,c:3}
constb={a:2,d:4,f:5}
pickDiffAttr(a,b)