Merge two arrays matching an id

Question

I have two arrays like

var members = [{docId: \"1234\", userId: 222}, {docId: \"1235\", userId: 333}];
var memberInfo = [{id: 222, name: \"test1\"}, {id: 333         


        

Answer 1

A solution using underscore:

var finalArray = _.map(members, function(member){
    return _.extend(member, _.omit(_.findWhere(memberInfo, {id: member.userId}), 'id'));
});

1. _.map across the members
2. find the matching member info using _.findWhere
3. _.omit the id key from the matching member info
4. _.extend the member with the member info

Answer 2

Do a nested map and update the top level element with the additional field date where fields in the arrays match.

member.map(mem => {
    return memberInfo.map(info => {
        if (info.id === mem.userId) {
            mem.date = info.date;
            return mem;
        }
    }
}

Answer 3

On ES6 you can use .find and Object.assign() in vanilla javascript, no need of extra libraries.

let finalArray = [];
memberInfo.forEach(member => {
finalArray.push( Object.assign( {}, member, 
         { docId: members.find(m => m.userId === member.id).docId } 
    ))
});

Answer 4

var members = [{
    docId: "1234",
    userId: 222
}, {
    docId: "1235",
    userId: 333
}];
var memberInfo = [{
    id: 222,
    name: "test1"
}, {
    id: 333,
    name: "test2"
}];
var finalArray = [];

_.each(memberInfo, function (item) {
    finalArray.push(_.each(_.where(members, {
        userId: item.id
    }),

    function (element) {
        element.name = item.name
    }));
});

console.log(finalArray);

Fiddle example

Answer 5

You can achieve using foreach function and creating the third array and displaying it.

$scope.members = [{docId: "1234", userId: 222}, {docId: "1235", userId: 333}];
$scope.memberInfo = [{id: 222, name: "test1"}, {id: 333, name: "test2"}];
$scope.finalArray = [];

angular.forEach($scope.members, function(member) {
    angular.forEach($scope.memberInfo, function(memberInfo) {
      if(member.userId ==memberInfo.id) {
          var test = {
            docId : member.docId,
            userId: member.userId,
            name: memberInfo.name
          }
          $scope.finalArray.push(test);
      }
  });
});

Here is the working plunker:

http://embed.plnkr.co/QRB5v2cI6SZOdZgdqDVR/preview

Hope it helps!

Answer 6

function computeMembers(members, memberInfo) {
  return members.map(function(member) {
    member.name = memberInfo[getMemberById(member.userId, memberInfo)].name
    return member
  })

  function getMemberById(id, elements) {
    var index = elements.filter(function(element) {
      return element.id === id
    })[0]
    return elements.indexOf(index)
  }
}

console.log(computeMembers(members, memberInfo))