Add items in array angular 4

 First declare a class.

//anyfile.ts
export class Custom
{
  name: string, 
  empoloyeeID: number
}

Then in your component import the class

import {Custom} from '../path/to/anyfile.ts'
.....
export class FormComponent implements OnInit {
 name: string;
 empoloyeeID : number;
 empList: Array<Custom> = [];
 constructor() {

 }

 ngOnInit() {
 }
 onEmpCreate(){
   //console.log(this.name,this.empoloyeeID);
   let customObj = new Custom();
   customObj.name = "something";
   customObj.employeeId = 12; 
   this.empList.push(customObj);
   this.name ="";
   this.empoloyeeID = 0; 
 }
}

Another way would be to interfaces read the documentation once - https://www.typescriptlang.org/docs/handbook/interfaces.html