Angular Fundamentals:

Interpolation :

Pass data from component file to template called interpolation,We can pass variable & function to the template files like below,

import { Component, OnInit } from '@angular/core';

@Component({

  selector: 'app-topmenu',

  template: `

{{name}}

{{getsirname()}}

`,

  styles: []

})

export class TopmenuComponent implements OnInit {

  public name = "Dharmendra Singh";

  constructor() { }

  ngOnInit() {

  }

  getsirname(){

return "rajput";

}}

Pipes :

Pipes are used to change the data before display on the view, like uppercase.lowecase,slice etc.

selector: 'app-topmenu',
  template: `
{{name | uppercase}}
 {{name | lowercase}}
 {{ post | json }}  // 

...

`,
  styles: []

ng foor loop in angular with add class dynamic on last element 

<span *ngFor="let two of last_two; let last = last;">

<div class="single-top-post" [ngClass]="{'mt-10': last}"> .....

Here it will add the mt-10 class at the last element