Angular ngFor trackBy

app.component.ts

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

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  customers: any[];
  constructor() {
    this.customers = [
      {
          cust_code: 'cust001', cust_name: 'John Smith', Cust_address: 'USA',
          Cust_phone: '6737540477', Cust_email: 'john.smith@outlook.com', Cust_gender: 'Male'
      },
      {
        cust_code: 'cust002', cust_name: 'Lori Orona', Cust_address: 'USA',
        Cust_phone: '6729837538', Cust_email: 'lori.orona@gmail.com', Cust_gender: 'Female'
      },
      {
        cust_code: 'cust003', cust_name: 'Steve Oman', Cust_address: 'UK',
        Cust_phone: '4252573576', Cust_email: 'steve333@yahoo.com', Cust_gender: 'Male'
      }
    ];
  }
  getCustomers(): void {
    this.customers =  [
      {
          cust_code: 'cust001', cust_name: 'Renna Sky', Cust_address: 'USA',
          Cust_phone: '5426589045', Cust_email: 'renna@outlook.com', Cust_gender: 'Female'
      },
      {
        cust_code: 'cust002', cust_name: 'Robin Mathew', Cust_address: 'UK',
        Cust_phone: '5635875090', Cust_email: 'robin.mathew@gmail.com', Cust_gender: 'Male'
      },
      {
        cust_code: 'cust003', cust_name: 'Steve Khan', Cust_address: 'UAE',
        Cust_phone: '4252573576', Cust_email: 'steve333_k@yahoo.com', Cust_gender: 'Male'
      },
      {
        cust_code: 'cust004', cust_name: 'Rubina Mallick', Cust_address: 'Iran',
        Cust_phone: '2367569086', Cust_email: 'rubina.mallick@yahoo.com', Cust_gender: 'Female'
      },
      {
        cust_code: 'cust005', cust_name: 'Rubina Mallick', Cust_address: 'Iran',
        Cust_phone: '2367569086', Cust_email: 'rubina.mallick@yahoo.com', Cust_gender: 'Female'
      }
    ];
  }
}