<script src="https://cdn.staticfile.org/angular.js/1.6.6/angular.min.js"></script>

<div ng-app="myApp" ng-controller="myCtrl">

<p>给 id 一个别名 y.name，显示出来的 name 值，但实际还是 id 值。</p>

<select ng-init="selectPersonid=persons['caohui'].id" ng-model="selectPersonid"  ng-options="y.id as y.name for (x,y) in persons">

</select>

<p>

    id:{{selectPersonid}}

</p>

</div>

var app = angular.module('myApp', []);

app.controller('myCtrl', function($scope) {

    $scope.persons = {

        caohui: {  

            id:1,

            age: 27, 

            name:'a'

        },

        youlangta: {

            id:2,

            age: 20,

            name:'b'

        },

        chenyanchan: {

            id:3,

            age: 24,

            name:'c'

        }

    }

})