@cheatsheetSection Built-in directives @cheatsheetIndex 3 @description {@target ts}`import { CommonModule } from '@angular/common';`{@endtarget} {@target js}Available using the `ng.common.CommonModule` module{@endtarget} @cheatsheetItem syntax: `<section *ngIf="showSection">`|`*ngIf` description: Removes or recreates a portion of the DOM tree based on the `showSection` expression. @cheatsheetItem syntax: `<li *ngFor="let item of list">`|`*ngFor` description: Turns the li element and its contents into a template, and uses that to instantiate a view for each item in list. @cheatsheetItem syntax: `<div [ngSwitch]="conditionExpression"> <template [ngSwitchCase]="case1Exp">...</template> <template ngSwitchCase="case2LiteralString">...</template> <template ngSwitchDefault>...</template> </div>`|`[ngSwitch]`|`[ngSwitchCase]`|`ngSwitchCase`|`ngSwitchDefault` description: Conditionally swaps the contents of the div by selecting one of the embedded templates based on the current value of `conditionExpression`. @cheatsheetItem syntax: `<div [ngClass]="{active: isActive, disabled: isDisabled}">`|`[ngClass]` description: Binds the presence of CSS classes on the element to the truthiness of the associated map values. The right-hand expression should return {class-name: true/false} map.