Angular has always been a framework that prioritizes developer experience, and its latest release, Angular 17, is no exception. One of the key changes introduced in Angular 17 is a new syntax for control flow in templates. This new syntax is more expressive, efficient, and easier to maintain than the previous syntax.

Old Syntax vs. New Syntax

In Angular 16 and earlier, control flow was primarily handled using directives such as *ngIf, *ngFor, and *ngSwitch. These directives were powerful and flexible, but they could also be verbose and difficult to read.

<div *ngIf="showTable">
  <table>
    </table>
</div>

<div *ngFor="let item of items">
  <p>{{ item }}</p>
</div>

<div *ngSwitch="variable">
  <ng-template #case1>
    <p>Case 1</p>
  </ng-template>
  <ng-template #case2>
    <p>Case 2</p>
  </ng-template>
  <ng-template #default>
    <p>Default</p>
  </ng-template>
</div>

The new syntax for control flow in Angular 17 uses a more declarative approach, relying on keywords like @if, @else, @switch, @case, @default, @for, and @empty. This new syntax is more concise and easier to read, making it a more enjoyable development experience.

<div @if="showTable">
  <table>
    </table>
</div>

<ul @for="let item of items">
  <li>{{ item }}</li>
</ul>

<div @switch="variable">
  <case #case1>
    <p>Case 1</p>
  </case>
  <case #case2>
    <p>Case 2</p>
  </case>
  <default>
    <p>Default</p>
  </default>
</div>

Benefits of the New Syntax

The new syntax for control flow in Angular 17 offers several benefits over the old syntax:

• Improved readability: The new syntax is more concise and easier to read, making it easier to understand and maintain code.
• Enhanced expressiveness: The new syntax allows for more expressive control flow constructs, making it easier to write clear and concise code.
• Easier migration: Angular provides an automatic migration tool to help you seamlessly transition from the old syntax to the new syntax.

Conclusion

The new syntax for control flow in Angular 17 is a significant improvement over the old syntax. It is more expressive, efficient, and easier to maintain. If you are still using the old syntax, I encourage you to migrate to the new syntax as soon as possible. You will find that it is a more enjoyable and productive development experience.