TL;DR

Info

Transforms a number to a percentage string, formatted according to locale rules that determine group sizing and separator, decimal-point character, and other locale-specific configurations.

class PercentPipe {
  transform(value: string | number, digitsInfo?: string, locale?: string): string;
  transform(value: null, digitsInfo?: string, locale?: string): null;
  transform(value: string | number, digitsInfo?: string, locale?: string): string;
}

import { PercentPipe } from "@angular/common"

Angular Doc part of CommonModule