Angular.copy函数

时间:2015-06-04 22:34:06

标签: javascript angularjs

我最近在Angular教程中注意到以下代码...

<div ng-app="myApp" ng-controller="formCtrl">
  <form novalidate>
    First Name:<br>
    <input type="text" ng-model="user.firstName"><br>
    Last Name:<br>
    <input type="text" ng-model="user.lastName">
    <br><br>
    <button ng-click="reset()">RESET</button>
  </form>
  <p>form = {{user}}</p>
  <p>master = {{master}}</p>
</div>

<script>
var app = angular.module('myApp', []);
app.controller('formCtrl', function($scope) {
    $scope.master = {firstName: "John", lastName: "Doe"};
    $scope.reset = function() {
        $scope.user = angular.copy($scope.master);
    };
    $scope.reset();
});
</script>

关于这一行:$scope.user = angular.copy($scope.master);,是否可以简化为:$scope.user = $scope.master;看到$scope.master在这种情况下将成为不可变常量?

1 个答案:

答案 0 :(得分:3)

当您使用对象在JavaScript中执行angular.copy时,您只是分配引用,而不是创建新对象(新引用)。在这种情况下,var obj1 = {}, var obj2 = {} obj1 !== obj2; // true obj1 = obj2; obj1 === obj2; // true obj1 = angular.clone(obj2); obj1 !== obj2; // true 会创建一个新对象。

在代码中:

{{1}}