js数组的多条件筛选

问题：有以下数组

var reportList = [
	{ reportName: '报告一', reportType: 1, reportTime: '20190524', isRelease: true },
	{ reportName: '报告二', reportType: 2, reportTime: '20190321', isRelease: true },
	{ reportName: '报告三', reportType: 1, reportTime: '20180324', isRelease: true },
	{ reportName: '报告四', reportType: 2, reportTime: '20190111', isRelease: false },
	{ reportName: '报告五', reportType: 1, reportTime: '20180424', isRelease: false },
	{ reportName: '报告六', reportType: 2, reportTime: '20190228', isRelease: true },
	{ reportName: '报告七', reportType: 1, reportTime: '20180324', isRelease: true },
	{ reportName: '报告八', reportType: 2, reportTime: '20171111', isRelease: true },
];

其中reportType表示报告类型，1为检查报告，2为检验报告；isRelease:表示改报告是否已发布；处理该数据得到四个数组：
1. 已发布检验报告
2. 已发布检查报告
3. 未发布检验报告
4. 未发布检查报告
并且将时间处理成2019-06-25的格式

解答：

var reportList = [
      { reportName: '报告一', reportType: 1, reportTime: '20190524', isRelease: true },
      { reportName: '报告二', reportType: 2, reportTime: '20190321', isRelease: true },
      { reportName: '报告三', reportType: 1, reportTime: '20180324', isRelease: true },
      { reportName: '报告四', reportType: 2, reportTime: '20190111', isRelease: false },
      { reportName: '报告五', reportType: 1, reportTime: '20180424', isRelease: false },
      { reportName: '报告六', reportType: 2, reportTime: '20190228', isRelease: true },
      { reportName: '报告七', reportType: 1, reportTime: '20180324', isRelease: true },
      { reportName: '报告八', reportType: 2, reportTime: '20171111', isRelease: true },
    ];

    const arr1 = [];
    const arr2 = [];
    const arr3 = [];
    const arr4 = [];

    reportList.forEach((item) => {
      const temp = item.reportTime;
      item.reportTime = temp.substr(0,4) + '-' + temp.substr(4,2) + '-' + temp.substr(6,2)
      if (item.reportType == 1) {
        if (item.isRelease) {
          arr1.push(item);
        } else {
          arr2.push(item);
        }
      } else {
        if (item.isRelease) {
          arr3.push(item);
        } else {
          arr4.push(item);
        }
      }
    })

    console.log(arr1);
    console.log(arr2);
    console.log(arr3);
    console.log(arr4);