如何将对象的属性与对象数组的属性匹配？

Question

I have two arrays of objects, hList and sList . I am trying to give each object in sList a property that matches an hList.ID , if one exists and is not already set. Im kind of tangled in the logic though, can someone help me out?

  var sList=[{name:"s1",id:"a"},{name: "s2",id:"b"},{name: "s3",id:"c"},{name: "s4",id:"d"}];
  var hList=[{name: "h1",id:"x"},{name: "h2",id:"y"},{name: "h3",id:"z"}];

so far I have:

try{    
  for(i in sList)
  {
    var s=sList[i];
    //find hList object that matches sList.id value
    var h=_.filter(hList.id,function(i){return(i==s.hID)});
    //if no hList.id match the sList.hID

    //find hList object that doesnt match any 

    //set the source id to the hList object id 

  }

}catch(err){console.log("err: ",err);}

GOAL: (only one hList.id can match an sList.hID . If an hList.id doesnt exist the sList.hID should be undefined.)

var sList=[{name:"s1",id:"a",hID:"x"},{name: "s2",id:"b",hID="y"},{name: "s3",id:"c",hID="z"},{name: "s4",id:"d",hID=undefined}]; //goal: set sList.hID to match an hList.id
var hList=[{name: "h1",id:"x"},{name: "h2",id:"y"},{name: "h3",id:"z"}];

Answer 1

 var sList=[{name:"s1",id:"a"},{name: "s2",id:"b"},{name: "s3",id:"c"},{name: "s4",id:"d"}]; var hList=[{name: "h1",id:"x"},{name: "h2",id:"y"},{name: "h3",id:"z"}]; sList = sList.map((item, index) => { item.hId = hList[index] ? hList[index].id : undefined; return item }) console.log(sList);