(vue)复合型输入框el-input输入数字类型，e，+，-等特殊符号可以输入

效果

代码

<el-form-item label="分数区间">
  <el-input
    placeholder="请输入内容"
    v-model.number="formInline.scoreIntervalValue"
    class="input-with-select"
    type="number"
  >
    <el-select
      v-model="formInline.scoreInterval"
      slot="prepend"
      placeholder="请选择"
      style="width:100px"
    >
      <el-option v-for="item in gradeOptions" :key="item" :label="item" :value="item"></el-option>
    </el-select>
  </el-input>
</el-form-item>

gradeOptions: [">", "<", "="],