Checkbox issue in the mat table-Angular7

Question

The previously checked checked-boxes in the mat table are not being counted when we select a new one. The entire checkbox column selection which is handled by a single checkbox which is in the header doesn't take into account of the newly checked or unchecked data.

Answer 1

To solve this we have to pass the index position in selection in the component.ts file:

Ex :

selection = new SelectionModel<PeriodicElement>(true, [this.dataSource.filteredData[1]);