<html><script src="https://cdn.staticfile.net/angular.js/1.6.9/angular.min.js"></script> <body ng-app=""><p>试着在输入框中输入内容：</p><form name="myForm"><input name="myInput" ng-model="myInput" required></form><p>输入框的有效状态是：</p><h1>{{myForm.myInput.$valid}}</h1></body></html>