Difference between [routerLink] and routerLink

问题:

What is the difference between [routerLink] and routerLink ? How should you use each one?

回答1:

You'll see this in all the directives:

When you use brackets, it means you're passing a bindable property (a variable).

  <a [routerLink]="routerLinkVariable"></a>

So this variable (routerLinkVariable) could be defined inside your class and it should have a value like below:

export class myComponent {

    public routerLinkVariable = "/home"; // the value of the variable is string!

But with variables, you have the opportunity to make it dynamic right?

export class myComponent {

    public routerLinkVariable = "/home"; // the value of the variable is string!


    updateRouterLinkVariable(){

        this.routerLinkVariable = '/about';
    }

Where as without brackets you're passing string only and you can't change it, it's hard coded and it'll be like that throughout your app.

<a routerLink="/home"></a>

UPDATE :

The other speciality about using brackets specifically for routerLink is that you can pass dynamic parameters to the link you're navigating to:

So adding a new variable

export class myComponent {
        private dynamicParameter = '129';
        public routerLinkVariable = "/home"; 

Updating the [routerLink]

  <a [routerLink]="[routerLinkVariable,dynamicParameter]"></a>

When you want to click on this link, it would become:

  <a href="/home/129"></a>

回答2:

Assume that you have

const appRoutes: Routes = [
  {path: 'recipes', component: RecipesComponent }
];

<a routerLink ="recipes">Recipes</a>

It means that clicking Recipes hyperlink will jump to http://localhost:4200/recipes

Assume that the parameter is 1

<a [routerLink] = "['/recipes', parameter]"></a>

It means that passing dynamic parameter, 1 to the link, then you navigate to http://localhost:4200/recipes/1