javascript - 如何检查并提醒是否有重复项插入到我的表中？

Question

对于通过“添加”按钮添加的每个品牌和型号，我需要检查是否有重复项，如果有重复项则设置警报并且不让它添加到表中。似乎无法找到解决方案...

下面是我正在处理的初学者元素的完整代码。对于这篇文章，我提前表示歉意，这是我第一次来到这里...谢谢大家。

<div>
 <div>Make: <input type="text" ng-model="make"></div>
 <div>Model:<input type="text" ng-model="model"></div>
 <button ng-click="add()">Add</button>

    <tr>
        <th>Make</th>
        <th>Model</th>
    </tr>
    <tr ng-repeat="car in cars" ng-click="rowClick(car)">
        <td>{{car.make}}</td>
        <td>{{car.model}}</td>
    </tr>

  <table class="table carsTable">
    <tr>
        <th>Make</th>
        <th>Model</th>
    </tr>
    <tr ng-repeat="car in cars" ng-click="rowClick(car)">
        <td>{{car.make}}</td>
        <td>{{car.model}}</td>
    </tr>

<script>
var carsApp = angular.module('carsApp', []);



carsApp.controller('carController', function ($scope){

   $scope.cars = [];

  $scope.add = function () {



    $scope.cars.push({
       make: $scope.make,
       model: $scope.model

    });

    $scope.make = null;
    $scope.model = null;

  };

  $scope.rowClick = function(car){
      $scope.make= car.make;
      $scope.model= car.model;
  };

  $scope.alert = function(){
      alert('Already exists in table');

  }

}); 

Answer 1

您可以通过检查数组中的每个 car(比较品牌和型号)来检查重复项 - 您可以使用 Array.some 来完成此操作(返回一个 bool 值，如果数组中的任何元素都符合条件):

在您的添加函数中:

var hasDuplicates = $scope.cars.some(car => car.make == $scope.make && car.model == $scope.model);

if (hasDuplicates) {
    alert("Car already exists");
} else {
    $scope.cars.push({
       make: $scope.make,
       model: $scope.model
    });
}

如果不能使用箭头语法:

var hasDuplicates = $scope.cars.some(function(car) {
    return car.make == $scope.make && car.model == $scope.model;
});