Angular 5 Constant

Angular Constant & Global Variables | Angular 9, 8, 7, 6, 5, 4, 2

How to CREATE constant in your Angular Apps? 

A constant is a value that can’t be changed by the program during normal execution.
Constants are of fixed values that do not change during the execution of a program. There are various types of constants. These can be :-
1.      Numeric
2.      Character
3.      Integer

4.      Other types

And constant class looks like

export class AppConstants {
    public static get baseURL(): string { return "http://localhost:4200/api"; }

And Use of constant in Services –

import { Injectable } from '@angular/core';
import {HttpClient, HttpParams, HttpHeaders} from "@angular/common/http";
import { Employee } from './employee';
import{ AppConstants} from '../app/constants'

export class EmployeeService {
  //variable initialization
  headers : any;
  _baseURL : string;

  //constructor initialization
  constructor(private _htc:HttpClient) {
      this.headers = new HttpHeaders().set('content-type', 'application/json');
      this._baseURL = AppConstants.baseURL;

  // POST employee - for creating a New employee.
  addEmployee(emp :any){
    var employee = {,
    return<Employee>(this._baseURL+'/Employees/Add', employee, (this.headers));

  //DELETE employee - for delete employee.
  deleteEmployee(id :string){    
    return this._htc.delete<Employee>(this._baseURL+'/Employees/Delete/'+id);


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