JAVASCRIPT

how to make a 3*3 grid using html,css and javascript

.grid {
  display: table;
  border-spacing: 2px
}
.row {
  display: table-row
}
.cell {
  width: 100px;
  height: 100px;
  background: black;
  display: table-cell;
}
.row div:last-child {
  background: blue
}