javascript - 动态创建一个数组，然后循环另一个数组来比较数据是否存在

Question

我想要实现的是动态创建一个数组，然后使用该数组与另一个数组(如果数据存在)进行比较。

现在发生的情况是，比较数组的代码在数组创建完成之前执行。本质上，我将数据与空数组进行比较。

我可以使用什么技术让代码完全执行code a，然后当code a完成时执行code b？

var awayTeamPlayersPlayedArray = [];
vm.awayTeamPlayers = $firebaseArray(awayTeamPlayersQuery);

// add data to awayTeamPlayersPlayedArray
angular.forEach(vm.awayTeamPlayersPlayed, function(value, key) {
    var awayTeamPlayerRef = new Firebase(FIREBASE_URL + 'players/' + key);
    var awayTeamPlayer = $firebaseObject(awayTeamPlayerRef);
    awayTeamPlayer.$loaded().then(function() {
        awayTeamPlayersPlayedArray.push(awayTeamPlayer.name);
        console.log(awayTeamPlayersPlayedArray)
    });
});

// loop through vm.awayTeamPlayers to see if they exist in awayTeamPlayersPlayedArray
angular.forEach(vm.awayTeamPlayers, function(value, key) {
    if(awayTeamPlayersPlayedArray.indexOf(value.name) > -1) {
        console.log(value.name + ' yes');
    } else {
        console.log(value.name + ' no');
    }
});

Answer 1

您应该在所有 Promise 完成后使用循环。

var allPromises = [];
// add data to awayTeamPlayersPlayedArray
angular.forEach(vm.awayTeamPlayersPlayed, function(value, key) {
  var awayTeamPlayerRef = new Firebase(FIREBASE_URL + 'players/' + key);
  var awayTeamPlayer = $firebaseObject(awayTeamPlayerRef);
  var promise = awayTeamPlayer.$loaded().then(function() {
    awayTeamPlayersPlayedArray.push(awayTeamPlayer.name);
    console.log(awayTeamPlayersPlayedArray);
  });
  allPromises.push(promise);
});
$q.all(allPromises).then(function() {
  // loop through vm.awayTeamPlayers to see if they exist in awayTeamPlayersPlayedArray

  angular.forEach(vm.awayTeamPlayers, function(value, key) {
    if(awayTeamPlayersPlayedArray.indexOf(value.name) > -1) {
      console.log(value.name + ' yes');
    } else {
      console.log(value.name + ' no');
    }
  });
});