how to set width of datatable? code example

Example 1: datatables change width of columns

$('#example').dataTable( {
  "autoWidth": false, // might need this
  "columns": [
    { "width": "20%" },
    null, // automatically calculates
    null  // remaining width
  ]
} );

Example 2: datatable column width

columnDefs: [
            { width: 200, targets: 0 }
        ],