如何通过JSONPath获取符合条件的数组项中的单个Lossyear值？

现有如下LossHistory JSON数据：

{"LossHistory": {
  "LossDetails": [
    {
      "LineOfBusinessCode": "General Liab - Excess",
      "Lossyear": 2018,
      "NumberOfTotalClaims": 8,
      "PaidLosses": 500,
      "PaidExpense": 80000,
      "Outstandingreserve": 800,
      "TotalIncurred": 800,
      "valuationDate": "2023-12-06T00:00:00",
      "LargeClaim": 700,
      "NumberOfOpenClaims": 6,
      "carrierName": "Hrst",
      "ClaimSource": "Manual"
    },
    {
      "LineOfBusinessCode": "General Liab - Excess",
      "Lossyear": 2019,
      "NumberOfTotalClaims": 8,
      "PaidLosses": 500,
      "PaidExpense": 80000,
      "Outstandingreserve": 800,
      "TotalIncurred": 800,
      "valuationDate": "2023-12-06T00:00:00",
      "LargeClaim": 700,
      "NumberOfOpenClaims": 6,
      "carrierName": "Hrst",
      "ClaimSource": "Manual"
    },
    {
      "LineOfBusinessCode": "Auto",
      "Lossyear": 2018,
      "NumberOfTotalClaims": 8,
      "PaidLosses": 500,
      "PaidExpense": 80000,
      "Outstandingreserve": 800,
      "TotalIncurred": 800,
      "valuationDate": "2023-12-06T00:00:00",
      "LargeClaim": 700,
      "NumberOfOpenClaims": 6,
      "carrierName": "Hrst",
      "ClaimSource": "Manual"
    }
  ]
}}

使用JSONPath表达式：

$..LossDetails[?(@.LineOfBusinessCode == 'General Liab - Excess')].Lossyear

得到的结果是一个数组：

[
   2018,
   2019
]

若要获取数组中的单个值（比如第一个元素2018），只需在原JSONPath表达式末尾添加索引下标即可，数组下标从0开始计数。

修改后的JSONPath表达式：

$..LossDetails[?(@.LineOfBusinessCode == 'General Liab - Excess')].Lossyear[0]

执行后将得到单个值：

2018

如果需要获取第二个值2019，只需把下标改为[1]即可。

内容的提问来源于stack exchange，提问作者Rajesh Senapati