Compare two arrays and concat without duplicates - angularjs

Question

I have two arrays. I can push and splice by clicking on a word in searchWords, which adds or removes a word to the currentWordlist.
What I want to have is a button that transfers all the searchWords to the currentWordlist, without overwriting the words that are actually on the currentWordlist.
I came up with this code:
$scope.addAll = function () {
var searchWords = [];
var currentWords = [];
// safes all searchwords to the array
for (var i = 0; i < $scope.searchWords.length; i++) {
searchWords.push($scope.searchWords[i]);
}
// safes all currentwords to the array
for (var j = 0; j < $scope.currentWordlist.length; j++) {
currentWords.push($scope.currentWordlist[j]);
}
console.log("searchWords " + searchWords.length);
console.log("currentWords " + currentWords.length);
angular.forEach(searchWords, function(value1, key1) {
angular.forEach(currentWords, function(value2, key2) {
if (value1._id !== value2._id) {
$scope.currentWordlist.push(value1);
}
});
});
};
I go through both of the arrays and safe them so that I can use the arrays inside my two angular.forEach to check if there are duplicates. If I don't push to the currentWordlist. But it's not working. I get an [ngRepeat:dupes] error, but I cannot use track by $index because otherwise removing from the list removes the wrong word. I think I am doing something critically wrong here, but I couldn't find out what so far (hours of trial and error :0)

Answer 1

I would suggest to use angular unique filter with ng-repeat directive. The code could be as follows:
$scope.addAll = function () {
// use angular.copy to create a new instance of searchWords
$scope.combinedWords = angular.copy($scope.searchWords).concat($scope.currentWordlist);
};
And then in your view:
<div ng-repeat="word in combinedWords | unique:'_id'">
{{word}}
</div>
Usage:
colection | uniq: 'property'
It also possible to filter by nested properties:
colection | uniq: 'property.nested_property'

Answer 2

You can simply do like this
angular.forEach($scope.searchWords, function(value1, key1) {
var temp=true;
angular.forEach($scope.currentWordlist, function(value2, key2) {
if (value1.id === value2.id)
temp=false;
});
if(temp)
$scope.currentWordlist.push(value1);
});
var app = angular.module("app", []);
app.controller("ctrl", function($scope) {
$scope.searchWords=[{id:1,name:'A'},{id:2,name:'B'},{id:1,name:'A'},{id:4,name:'D'}];
$scope.currentWordlist=[];
$scope.addAll = function() {
angular.forEach($scope.searchWords, function(value1, key1) {
var temp=true;
angular.forEach($scope.currentWordlist, function(value2, key2) {
if (value1.id === value2.id)
temp=false;
});
if(temp)
$scope.currentWordlist.push(value1);
});
console.log($scope.currentWordlist);
};
});
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app="app" ng-controller="ctrl">
<button ng-click="addAll(newWord)">Add</button>
<div>{{currentWordlist}}</div>
</div>