block includes
  include ../_util-fns
  - var _JavaScript = 'JavaScript';
  //- Double underscore means don't escape var, use !{__var}.
  - var __chaining_op = '; or ,';
  - var __new_op = 'new';
  - var __objectAsMap = 'object';
:marked
  Our Angular application manages what the user sees and can do, achieving this through the interaction of a Component class instance (the *component*) and its user-facing template.
  我们的Angular应用管理着用户之所见和所为,并通过Component类的实例(*component*)和面向用户的模板来与用户交互。
  Many of us are familiar with the component/template duality from our experience with model-view-controller (MVC) or model-view-viewmodel (MVVM). In Angular,  the component plays the part of the controller/viewmodel, and the template represents the view.
  从使用模型-视图-控制器(MVC)或模型-视图-视图模型(MVVM)的经验中,很多用户都熟悉了组件/模板这两个概念。
  在Angular中,组件扮演着控制器或视图模型的角色,模板则扮演视图的角色。
  Let’s find out what it takes to write a template for our view. We’ll cover these basic elements of template syntax:
  我们来看看写视图的模板都需要什么。我们将覆盖模板语法中的下列基本元素:
  * [HTML](#html)
  * [HTML](#html)
  * [Interpolation](#interpolation)
  * [插值表达式](#interpolation)
  * [Template expressions](#template-expressions)
  * [模板表达式](#template-expressions)
  * [Template statements](#template-statements)
  * [模板语句](#template-statements)
  * [Binding syntax](#binding-syntax)
  * [绑定语法](#binding-syntax)
  * [Property binding](#property-binding)
  * [属性绑定](#property-binding)
  * [Attribute, class, and style bindings](#other-bindings)
  * [HTML属性、class和style绑定](#other-bindings)
  * [Event binding](#event-binding)
  * [事件绑定](#event-binding)
  * [Two-way data binding with `NgModel`](#ngModel)
  * [使用`NgModel`进行双向数据绑定](#ngModel)
  * [Built-in directives](#directives)
  * [内置指令](#directives)
    * [NgClass](#ngClass)
    * [NgClass](#ngClass)
    * [NgStyle](#ngStyle)
    * [NgStyle](#ngStyle)
    * [NgIf](#ngIf)
    * [NgIf](#ngIf)
    * [NgSwitch](#ngSwitch)
    * [NgSwitch](#ngSwitch)
    * [NgFor](#ngFor)
    * [NgFor](#ngFor)
  * [* and <template>](#star-template)
  * [* 与 <template>](#star-template)
  * [Template reference variables](#ref-vars)
  * [模板引用变量](#ref-vars)
  * [Input and output properties](#inputs-outputs)
  * [输入输出属性](#inputs-outputs)
  * [Template expression operators](#expression-operators)
  * [模板表达式操作符](#expression-operators)
    * [pipe](#pipe)
    * [管道](#pipe)
    * [safe navigation operator (?.)](#safe-navigation-operator)
    * [“安全导航操作符”(?.)](#safe-navigation-operator)
  The