el-select选中特定项的触发事件

需求：下拉框中如选中自定义时间，则出现弹窗

实现代码：

html

 <el-select v-model="type" clearable @change="fnEdit">
    <el-option  v-for="item in typeOptions" :key="item.value" :label="item.label" :value="item.value"></el-option>
 </el-select>

JS

 type:0,
 typeOptions:[
     {label:'今日',value:0},
     {label:'本周',value:1},
     {label:'本月',value:2},
     {label:'全年',value:3},
     {label:'自定义时间',value:4},
  ],

fnEdit(vId){
     if(vId== 4){ this.dialogDateVisible = true; }
}