My ng-model is not getting updated why - angularjs

Question

Hey guys here is my code it is not running at all i can't understand i just want to understand why it is not running
http://plnkr.co/edit/vvv3aavAopBhXlc1miUI
var app = angular.module('plunker', []);
app.controller('MainCtrl', function($scope) {
$scope.user=$scope.name;
console.log($scope);
});

Answer 1

This line is wrong:
$scope.user=$scope.name;
You are trying to assign the value of one property on your scope (user) from a non defined property (name)
I think you should be using this kind of approach
app.controller('MainCtrl', function($scope) {
$scope.user="user"
$scope.name="name";
console.log($scope);
});
For demo purposes this will hard code 'user' and 'name' in your input fields, but if you are trying to capture values entered by the user you will probably be using a button with a click handler and in the handler function you can access the user and name values on your scope for further processing, e.g. submit to server via $http

Answer 2

From what I understand you want the second update field to get updated when you type something in the first.
Why it is not working now?
At the moment you are only assigning the value of $scope.name to $scope.user when the controllers loads at start (undefined). You are not watching the value and assigning it to $scope.user when it changes so the value of $scope.user does not update.
Some options on how to make it work
You could use the ngChange directive
In your HTML:
<input type="text" ng-model="name" ng-change="updateUser()">
<input type="text" ng-model="user">
in your controller:
$scope.updateUser = function() {
$scope.user=$scope.name; }
ng-change (Plunkr)
Or (depending on what you are trying to achieve), you could give them the same ng-model:
<input type="text" ng-model="name">
<input type="text" ng-model="name">
same ng-model (Plunkr)