Javascript Angular 无法设置未定义的属性
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Angular cannot set property of undefined
提问by Paul Boutes
I can't quite figure out why the following isn't working:
我不太明白为什么以下不起作用：
main.html
主文件
<div class="MainCtrl">
<h1>{{message.test}}</h1>
</div>
main.js
主文件
angular.module('myApp')
.controller('MainCtrl', function(someService, $location, $scope) {
$scope.message.test = "blablabla";
}
});
When I run the code I can an error that states:
当我运行代码时，我可以看到一个错误：
TypeError: Cannot set property 'test' of undefined at new (http://localhost:9000/scripts/controllers/main.js:13:25) at invoke (http://localhost:9000/bower_components/angular/angular.js:4473:17) at Object.instantiate (http://localhost:9000/bower_components/angular/angular.js:4481:27) at http://localhost:9000/bower_components/angular/angular.js:9108:28at $route.link (http://localhost:9000/bower_components/angular-route/angular-route.js:977:26) at invokeLinkFn (http://localhost:9000/bower_components/angular/angular.js:8746:9) at nodeLinkFn (http://localhost:9000/bower_components/angular/angular.js:8246:11) at compositeLinkFn (http://localhost:9000/bower_components/angular/angular.js:7637:13) at publicLinkFn (http://localhost:9000/bower_components/angular/angular.js:7512:30) at name.$get.boundTranscludeFn (http://localhost:9000/bower_components/angular/angular.js:7656:16)
类型错误：无法在调用（http://localhost:9000/bower_components/angular/angular.js）时在新（http://localhost:9000/scripts/controllers/main.js:13:25）处设置未定义的属性“test” 。 js:4473:17) 在 Object.instantiate ( http://localhost:9000/bower_components/angular/angular.js:4481:27) 在http://localhost:9000/bower_components/angular/angular.js:9108: 28在 $route.link ( http://localhost:9000/bower_components/angular-route/angular-route.js:977:26) 在 invokeLinkFn ( http://localhost:9000/bower_components/angular/angular.js: 8746:9) 在 nodeLinkFn ( http://localhost:9000/bower_components/angular/angular.js:8246:11) 在复合链接 Fn( http://localhost:9000/bower_components/angular/angular.js:7637:13) 在 publicLinkFn ( http://localhost:9000/bower_components/angular/angular.js:7512:30) 在名称。 $get.boundTranscludeFn ( http://localhost:9000/bower_components/angular/angular.js:7656:16)
Clearly I'm missing something super obvious..
显然我错过了一些非常明显的东西..
回答by Paul Boutes
You're defining a property to an undefinedobject, you have to initialized your object before setting properties.
您正在为未定义的对象定义一个属性，您必须在设置属性之前初始化您的对象。
$scope.message = {};
$scope.message.test = 'bla';
回答by slomek
You should initialize your $scope.messageobject, but do it safely (just in case it's defined somewhere else, maybe in some circumstanes):
您应该初始化您的$scope.message对象，但要安全地进行（以防万一它在其他地方定义，也许在某些情况下）：
$scope.message = $scope.message || {};
$scope.message.test = "blablabla";
回答by John V
messagein your code is not an object, you must make it:
message在你的代码中不是一个对象，你必须让它：
$scope.message = { test: 'blablabla' };
回答by macrog
your test does not exist inside a message, you need to do $scope.message = {};before , $scope.message.test = "blablabla";
您的测试不存在于消息中，您需要在此$scope.message = {};之前进行，$scope.message.test = "blablabla";
