数组格式如下：

"industrySceneList": [
    {
        "mainIndustry": 1,
        "mainIndustryName": "林草",
        "sceneList": [
            {
                "subIndustry": 1,
                "subIndustryName": "森林防火"
            }
        ]
    },
    {
        "mainIndustry": 2,
        "mainIndustryName": "国土",
        "sceneList": [
            {
                "subIndustry": 141,
                "subIndustryName": "其它-1"
            },
            {
                "subIndustry": 11,
                "subIndustryName": "耕地保护"
            },
            {
                "subIndustry": 12,
                "subIndustryName": "矿山保护"
            }
        ]
    },
    {
        "mainIndustry": 12,
        "mainIndustryName": "其它-2",
        "sceneList": [
            {
                "subIndustry": 71,
                "subIndustryName": "其它-3"
            }
        ]
    }
],

第一种办法：通过map计数来判定：

onSubIndustryChange(industrySceneList) {
  let validIndust = true;
  let subIndustry = "";
  // 创建一个Map来存储subIndustry及其出现次数
  const subIndustryCounts = new Map();

  // 遍历industrySceneList
  industrySceneList.forEach(industryScene => {
    // 遍历当前场景列表中的sceneList
    industryScene.sceneList.forEach(scene => {
      // 获取当前subIndustryName的计数，如果不存在则默认为0
      const count = subIndustryCounts.get(scene.subIndustryName) || 0;
      // 将计数加1
      subIndustryCounts.set(scene.subIndustryName, count + 1);
    });
  });

  // 筛选出计数大于1的subIndustry，即重复的subIndustry
  const duplicates = Array.from(subIndustryCounts)
      .filter(([subIndustry, count]) => count > 1)
      .map(([subIndustry, _]) => subIndustry);

  //数组转String用逗号拼接
  subIndustry = duplicates.join(',');
  if (duplicates.length > 0) {
    validIndust = false;
    this.$message({
      message: '当前存在' +subIndustry+'重复，请检查后重试',
      type: 'error'
    });
  }
  return validIndust;
},

第二种办法：通过ES6 set数据类型

hasDuplicateIds(value) {
  console.log(value);
  let dupValid = true;
  const nonMinusOneItems = this.industryScenario.filter(item => item.mainIndustry == value);
  const uniqueNonMinusOneIds = new Set(nonMinusOneItems.map(item => item.mainIndustry));

  if(nonMinusOneItems.length !== uniqueNonMinusOneIds.size){
    this.$message({
      message: '行业不能重复',
      type: 'error'
    });
    dupValid = false;
  }
  return dupValid;
},

---------- 兄弟们更喜欢哪一种呢~