JAVASCRIPT

close bootstrap modal with javascript

$('#myModal').modal('hide');

modal dismiss

<!-- Button trigger modal -->
<button type="button" class="btn btn-primary" data-toggle="modal" data-target="#exampleModalCenter">
  Launch demo modal
</button>

<!-- Modal -->
<div class="modal fade" id="exampleModalCenter" tabindex="-1" role="dialog" aria-labelledby="exampleModalCenterTitle" aria-hidden="true">
  <div class="modal-dialog modal-dialog-centered" role="document">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" id="exampleModalLongTitle">Modal title</h5>
        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
          <span aria-hidden="true">×</span>
        </button>
      </div>
      <div class="modal-body">
        ...
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
        <button type="button" class="btn btn-primary">Save changes</button>
      </div>
    </div>
  </div>
</div>

when modal close event

$("yourid").on('hide.bs.modal', function(){
	// do it here
});

bs modal service close

this._bsModalRef.hide();

Close Modal

 .close.mat-button {
    position: absolute;
    top: 0;
    right: 0;
    padding: 5px;
    line-height: 14px;
    min-width: auto;
}
   <button class="close" mat-button [mat-dialog-close]="true">X</button>