scope

问题 In bash, if I define a variable inside a script (say, set_var.sh ), I can choose whether those definitions persist after "running" the script. This will depend on how I "run" the script, the options being: sh set_var.sh (variables do not persist) ./set_var.sh (variables do not persist, same as point 1) source set_var.sh (variables persist) This is irrespective from the variable being exported to the environment or not in set_var.sh . Can the same as items 1 and 3 above be achieved with

问题 I have the following issue: const value1 = "some value"; var value2 = "some value"; console.log(window["value1"]); // undefined console.log(window["value2"]); // some value I know that const is block scoped and that is the reason I cannot access it through the window object. My question is, is there any way to access a const variable using only a string identifier. If all I have access to is "value1", how do I get a handle on the actual value1? Is it even possible? 回答1: It appears that, block

问题 I have a contenteditable div like this: <div contenteditable="true" ng-model="name">{{ name }}</div> <input type="button" ng-click="checkScope()" value="Click me"> In my controller: var app = angular.module('sbAdminApp', []); app.controller('MyCtrl', function($scope) { $scope.name = 'Adrian'; $scope.checkScope = function(){ console.log($scope.name); } }); How can I get the latest value of contenteditable div using scope when I click the button? 回答1: you need a directive to work this app

问题 I have a contenteditable div like this: <div contenteditable="true" ng-model="name">{{ name }}</div> <input type="button" ng-click="checkScope()" value="Click me"> In my controller: var app = angular.module('sbAdminApp', []); app.controller('MyCtrl', function($scope) { $scope.name = 'Adrian'; $scope.checkScope = function(){ console.log($scope.name); } }); How can I get the latest value of contenteditable div using scope when I click the button? 回答1: you need a directive to work this app

问题 I'm trying to access a parent member variable from an extended class. But running the following code... class Mother(object): def __init__(self): self._haircolor = "Brown" class Child(Mother): def __init__(self): Mother.__init__(self) def print_haircolor(self): print Mother._haircolor c = Child() c.print_haircolor() Gets me this error: AttributeError: type object 'Mother' has no attribute '_haircolor' What am I doing wrong? 回答1: You're mixing up class and instance attributes. print self.

问题 The following code always prints the argument passed in to parameter a , regardless of the presence of a variable with the same name. Presumably because parameter identifiers are bound separately to variables in scope. Where are they positioned? Are they in the lexical environment? function foo(a, b = () => a) { var a = 1 console.log(b()) } foo() // undefined foo(2) // 2 Is it that var declarations end up in the special VariableEnvironment, while parameters are positioned in the

问题 I'm in JavaScript for a while, but there is still soo much things to learn. Now, I had found some interesting facts about Switch statement . I know that when you use case someValue : without break; it execute code in next case. switch (x) { case 0: case 1: doThis(); case 2: doSomethingElse(); break; } So, when x is 0 or 1 it execute doThis() and even doSomethingElse() , but why? . Will JavaScript interpret it into something like this: switch (x) { case (0 == x || 1 == x): doThis();

问题 I'm trying to understand the difference between the controller's $onDestroy method and $scope.$destroy() . Definition says that $onDestroy is called when the containing scope of the component needs to be destroyed. But isn't it the same case with $scope.$destroy()? As per the plunker I've created at https://plnkr.co/edit/9RlS8OLxAoyK80WPMJaN?p=preview , <div ng-controller="ParentController"> <button ng-click="func()">Parent</button> <br><br> <div ng-controller="ChildController"> <button ng

问题 I'm trying to understand the difference between the controller's $onDestroy method and $scope.$destroy() . Definition says that $onDestroy is called when the containing scope of the component needs to be destroyed. But isn't it the same case with $scope.$destroy()? As per the plunker I've created at https://plnkr.co/edit/9RlS8OLxAoyK80WPMJaN?p=preview , <div ng-controller="ParentController"> <button ng-click="func()">Parent</button> <br><br> <div ng-controller="ChildController"> <button ng

问题 I'm trying to understand the difference between the controller's $onDestroy method and $scope.$destroy() . Definition says that $onDestroy is called when the containing scope of the component needs to be destroyed. But isn't it the same case with $scope.$destroy()? As per the plunker I've created at https://plnkr.co/edit/9RlS8OLxAoyK80WPMJaN?p=preview , <div ng-controller="ParentController"> <button ng-click="func()">Parent</button> <br><br> <div ng-controller="ChildController"> <button ng