titlecase pipe in angular 4

Yes, you can use it like this

<h2>{{ 'ramesh rajendran' | titlecase }}</h2>

But, don't forget to import CommonModule into your module.

@NgModule({
  imports: [
    CommonModule,
    ...
  ],

Yes it is possible in TypeScript code. You'll need to call the Pipe's transform() method.

Your template:

<h2>{{ fullName }}</h2>

In your .ts:

import { TitleCasePipe } from '@angular/common';

export class App {

    fullName: string = 'ramesh rajendran';

    constructor(private titlecasePipe:TitleCasePipe ) { }

    transformName(){
        this.fullName = this.titlecasePipe.transform(this.fullName);
    }
}

You'll need to add TitleCasePipe in yout AppModule providers. You can call the transformation on button click or some other event in the typescript code.

Here is a link to PLUNKER DEMO