javascript - 类型错误 : undefined is not a function --- Need to troubleshoot

Question

我收到这个非常奇怪的错误

TypeError: undefined is not a function
    at h.$scope.getCoordDistance (http://run.plnkr.co/NDFxGL6q55m1601d/script.js:32464:21)
    at http://run.plnkr.co/NDFxGL6q55m1601d/script.js:32491:14
    at Array.forEach (native)
    at Object.q [as forEach] (https://ajax.googleapis.com/ajax/libs/angularjs/1.2.17/angular.min.js:7:280)
    at new <anonymous> (http://run.plnkr.co/NDFxGL6q55m1601d/script.js:32480:11)
    at d (https://ajax.googleapis.com/ajax/libs/angularjs/1.2.17/angular.min.js:34:479)
    at Object.instantiate (https://ajax.googleapis.com/ajax/libs/angularjs/1.2.17/angular.min.js:35:103)
    at https://ajax.googleapis.com/ajax/libs/angularjs/1.2.17/angular.min.js:66:467
    at https://ajax.googleapis.com/ajax/libs/angularjs/1.2.17/angular.min.js:53:250
    at q (https://ajax.googleapis.com/ajax/libs/angularjs/1.2.17/angular.min.js:7:386)

在网上搜索了大约一个半小时后，我完全不知道这意味着什么。有人知道这意味着什么吗？这是我的代码:

var app = angular.module('app', []);
app.controller('firstCtrl', function($scope) {
  var myLat,myLon,locLat,locLon;
  $scope.ASiteLocs = [{
    "name": "IL5077 BRUSSELS",
    "styleUrl": "#waypoint",
    "Point": {
      "coordinates": "-90.58543899999999,38.955472,0"
    }
  }, {
    "name": "IL5076 KAMPSVILLE",
    "styleUrl": "#waypoint",
    "Point": {
      "coordinates": "-90.661923,39.29403,0"
    }
  }, {
    "name": "IL5146 CARROLLTON",
    "styleUrl": "#waypoint",
    "Point": {
      "coordinates": "-90.39965700000001,39.309142,0"
    }
  }];//there are a couple thousand of these
  $scope.SSiteLocs = [/*More Locations*/];// but its too long
  $scope.SiteLocs = $scope.SSiteLocs.concat($scope.ASiteLocs);
  repoSortOrder = "site.name";
  navigator.geolocation.getCurrentPosition(GetLocation);

  function GetLocation(location, myLat, myLon) {
    $scope.myLat = location.coords.latitude;
    $scope.myLon = location.coords.longitude;

  } $scope.getCoordDistance = function(myLat, myLon,locLat, locLon) {


    var lat2 = $scope.myLat;
    var lon2 = $scope.myLon;
    var lat1 = $scope.locLat;
    var lon1 = $scope.locLon;

    var R = 3959; // Mean Earth radius in miles 
    var x1 = lat2 - lat1;
    var dLat = x1.toRad();
    var x2 = lon2 - lon1;
    var dLon = x2.toRad();
    var a = Math.sin(dLat / 2) * Math.sin(dLat / 2) +
      Math.cos(lat1.toRad()) * Math.cos(lat2.toRad()) *
      Math.sin(dLon / 2) * Math.sin(dLon / 2);
    var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
    $scope.d = R * c;
  }
 Number.prototype.toRad = function() {
      return this * Math.PI / 180;
    }

  angular.forEach($scope.SSiteLocs, function(object) {
    object.carrier = 'Sprint';
  })
  angular.forEach($scope.ASiteLocs, function(object) {
    object.carrier = 'AT&T';
  });

  angular.forEach($scope.SiteLocs, function(location, locLat, locLon) {
    var clength = location.Point.coordinates.length;
    if (location.Point.coordinates.substring(clength - 2, clength) === ",0") {
      location.Point.coordinates = location.Point.coordinates.substring(0, clength - 2).split(",");
      Lat = location.Point.coordinates[0];
      Lon = location.Point.coordinates[1];
      Com = ",";
      location.Point.coordinates = Lon.concat(Com, Lat);
    }
    $scope.locLat = location.Point.coordinates[0];
      $scope.locLon = location.Point.coordinates[1];
      $scope.getCoordDistance();
      location.distance = d;
  });


}); 

如果我尝试使用 parseInt(); 解析 myLat, myLon, locLat, locLon，我会收到此错误:

TypeError: Cannot read property 'toRad' of undefined
    at h.$scope.getCoordDistance (http://run.plnkr.co/NDFxGL6q55m1601d/script.js:46:45)
    at http://run.plnkr.co/NDFxGL6q55m1601d/script.js:73:14
    at Array.forEach (native)
    at Object.q [as forEach] (https://ajax.googleapis.com/ajax/libs/angularjs/1.2.17/angular.min.js:7:280)
    at new <anonymous> (http://run.plnkr.co/NDFxGL6q55m1601d/script.js:62:11)
    at d (https://ajax.googleapis.com/ajax/libs/angularjs/1.2.17/angular.min.js:34:479)
    at Object.instantiate (https://ajax.googleapis.com/ajax/libs/angularjs/1.2.17/angular.min.js:35:103)
    at https://ajax.googleapis.com/ajax/libs/angularjs/1.2.17/angular.min.js:66:467
    at https://ajax.googleapis.com/ajax/libs/angularjs/1.2.17/angular.min.js:53:250
    at q (https://ajax.googleapis.com/ajax/libs/angularjs/1.2.17/angular.min.js:7:386) 

非常感谢任何帮助!!!

这是该项目的一部分:http://plnkr.co/edit/nRQc7Ym0lsaK6jQwd626?p=preview

Answer 1

在从 navigator.geolocation.getCurrentPosition() 获取坐标之前，您正在运行 getCoordDistance()(顺便说一句，这是一个异步调用)。这意味着 $scope.myLat 和 $scope.myLon 都是 null/undefined，这会导致错误“无法读取属性 'toRad' of未定义”。

检查这个plunker