[]: 绑定属性

<div class="red">red</div>    // class为red
<div [class]="red">red</div>  // class为blue; 从变量red读取
 
//组件中
red: string = "blue";

(): 绑定事件

<div (click)="go()">gogo</div>
 
//组件中
go() {
 //...
}

{{}}: 插值

<div>{{good}}</div>   //<div>你好</div> 
 
//组件中
good: string = "你好";