⭐ What Are Structural Directives in Angular?

Structural directives change or control the structure of the DOM.

Examples:

• *ngIf

• *ngFor

• *ngSwitchCase

They all use micro-syntax, a special shorthand language inside templates.

🎯 What is Micro-Syntax?

Micro-syntax is the short, compact format Angular lets you write with structural directives.

For example:

is a shorthand for:

Micro-syntax = short form
Angular converts it into long <ng-template> form internally.

🧩 *1️⃣ Micro-Syntax for ngIf

Basic:

With else:

What Angular actually expands to:

🧩 *2️⃣ Micro-Syntax for ngFor

Basic:

Micro-syntax keywords:

• let → create local variables

• of → loop over list

• index, first, last, even, odd → context variables

Full micro-syntax:

Expanded form (Angular internally does this):

🧩 *3️⃣ Micro-Syntax for ngSwitch

Usage:

Angular converts each structural directive into an <ng-template> behind the scenes.

⭐ General Rules of Structural Directive Micro-Syntax

✔ Rule 1: * always turns element into <ng-template>

Example:

Becomes:

✔ Rule 2: You can use semicolons (;) to separate instructions

✔ Rule 3: Use let to define template variables

✔ Rule 4: Use keyword as to give alias

Same as:

🎉 Example: Combined Micro-Syntax (Advanced)

Angular internally treats them as nested <ng-template>.

✔️ Summary Table

🎯 Summary in One Line

Micro-syntax is Angular’s shorthand way of writing structural directives, which Angular expands into <ng-template> code internally.