function setValue(property="",value,target={}){
const propertyArr=property.split(".");
return propertyArr.reduce((pre,cur,index)=>{
if(index===propertyArr.length-1){
pre[cur]=value;
return target;
}
pre[cur]={};
return pre[cur];
},target)
}
const obj={e:1};
console.log(obj,setValue('a.b.c.d.e',1,obj));