问题：
<!DOCTYPE html><html><head><meta charset="utf-8"><script src="http://cdn./libs/angular.js/1.4.6/angular.min.js"></script> </head><body><div ng-app="myApp"><p ng-controller = "myContrl">结果为 <span ng-bind="" ></span><input type="text" ng-model="first">{{first+second}}</p></div><script>var app = angular.module("myApp",[]);app.controller("myContrl",function($scope){$scope.first = 5;$scope.second =10;});</script></body></html>
显示结果为
但是，我要是输入50，想要结果为60
因为这个是字符串类型需要转换成数字类型
解决方法：
<!DOCTYPE html><html><head><meta charset="utf-8"><script src="http://cdn./libs/angular.js/1.4.6/angular.min.js"></script> </head><body><div ng-app="myApp"><p ng-controller = "myContrl">结果为 <span ng-bind="" ></span><input type="text" ng-model="first">{{first *1+second*1}}</p></div><script>var app = angular.module("myApp",[]);app.controller("myContrl",function($scope){$scope.first = 5;$scope.second =10;});</script></body></html>
显示即可正常 即是在{{first *1+second*1}}显示的时候，转换了一下
或者，启用事件监听
<!DOCTYPE html><html><head><meta charset="utf-8"><script src="http://cdn./libs/angular.js/1.4.6/angular.min.js"></script> </head><body><div ng-app="myApp"><p ng-controller = "myContrl">结果为 <span ng-bind="" ></span><input type="text" ng-model="first">{{total}}</p></div><script>var app = angular.module("myApp",[]);app.controller("myContrl",function($scope){$scope.first = 5;$scope.second =10;$scope.total = parseInt($scope.first)+parseInt($scope.second);$scope.$watch(function(){return $scope.first;},function(newValue,oldValue){if(newValue != oldValue){$scope.total = parseInt($scope.first)+parseInt($scope.second);}});});</script></body></html>
也能输出正确结果
