数据源为数组时

<select ng-init="selectedName = names[0]" ng-model="selectedName" ng-options="x.title for x in names">
</select>

则其中每个option的text为{{x.title}}而选中时的ng-model为x对象
而如果用ng-repeat,每个option提供的ng-model即其value,只能为字符串

数据源是对象时

• (x,y)对应着(key,value)

<select ng-model="selectedCar" ng-options="y.brand for (x, y) in cars">
</select>

$scope.cars = {
  car01 : {brand : "Ford", model : "Mustang", color : "red"},
  car02 : {brand : "Fiat", model : "500", color : "white"},
  car03 : {brand : "Volvo", model : "XC90", color : "black"}
};