如何检查多选下拉选项?

how to cheked multiselect dropdown option?

我必须要多个 select 下拉选项 我在 ajax

中获取了结果
$.ajax({
    type    : 'POST',
    data: {id:id},
    url     : url,
    dataType  : 'json',
    success: function(data){
        var len = data.length;
        for (var i = 0; i < len; i++) {
            var templatename1 = data[i]['templatename'];
            var fields = data[i]['fields'];
            $('#selectColumn1').val(fields);
        } 
    }
});

var fields = data[i]['fields']; 中的响应类似于 a,b,c,d(逗号分隔)

那么如何 select 在下拉复选框 select 中像 a,b,c 选项那样处理记录?

 $.ajax({
    type    : 'POST',
    data: {id:id},
    url     : url,
    dataType  : 'json',
    success: function(data){
        var len = data.length;
        for (var i = 0; i < len; i++) {
            var templatename1 = data[i]['templatename'];
              if(data[i]['fields']){ 
                 var fields = data[i]['fields'].split(","); // you have to convert comma seperated string into array
              }
              $('#selectColumn1').val(fields);
              $("#selectColumn1").multiselect("refresh"); // To refresh multiselect
        }
    }
});