Updated to angular 11

Now compiling with strict mode in typescript
Need to error checking now

bookie/src/app/sales/discount/discount.component.ts

@@ -11,9 +11,9 @@ import { DiscountDataSource } from './discount-datasource';
   styleUrls: ['./discount.component.css'],
 })
 export class DiscountComponent {
-  list: any[];
+  list: any[] = [];
   form: FormGroup;
-  dataSource: DiscountDataSource;
+  dataSource: DiscountDataSource = new DiscountDataSource([]);
 
   displayedColumns = ['name', 'discount'];
 
@@ -22,7 +22,9 @@ export class DiscountComponent {
     private fb: FormBuilder,
     @Inject(MAT_DIALOG_DATA) public data: Observable<any[]>,
   ) {
-    this.createForm();
+    this.form = this.fb.group({
+      discounts: '',
+    });
     this.data.subscribe((list: any[]) => {
       this.list = list;
       this.form.setControl(
@@ -40,12 +42,6 @@ export class DiscountComponent {
     });
   }
 
-  createForm() {
-    this.form = this.fb.group({
-      discounts: '',
-    });
-  }
-
   accept(): void {
     const array = this.form.get('discounts') as FormArray;
     this.list.forEach((item, index) => {