How to CREATE constant in your Angular Apps?
A constant is a value that can’t be changed by the program during normal execution.
And constant class looks like –
A constant is a value that can’t be changed by the program during normal execution.
OR
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'
@Injectable()
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
= {
name:emp.name,
Dep:emp.Dep,
Des:emp.Des
}
return this._htc.post<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);
}
}