Angular Old vs New Syntax: A Practical Cheat Sheet (*ngIf @if, Signals, and More)

You open a two-year-old Angular codebase and see *ngIf everywhere. You open a job posting sample and the code uses @if. Nobody sent a memo explaining when that changed.

Here's every major old-to-new swap, side by side, with what actually changed underneath not just the syntax.

Conditionals: *ngIf → @if

Old:

<div *ngIf="isLoggedIn; else guestBlock">