如何访问此 JSON 字符串中的某些值？答案

【问题标题】：How can I access certain values in this JSON string?如何访问此 JSON 字符串中的某些值？
【发布时间】：2021-06-01 10:12:49
【问题描述】：

这是我的 JSON 输出。这是来自 API 的响应。我需要访问到达时间。我发现在 Javsacript 和 Jquery 中成功执行此操作的唯一方法是执行此操作有没有更简单的方法来访问这些数据？

JSON 输出：

{
    "routes": [
        {
            "id": "f8b5d90a-d2b5-4149-b058-087c27e52fd0",
            "sections": [
                {
                    "id": "c16d58b7-7e2a-4ded-b8b7-96972d4ab0e4",
                    "type": "vehicle",
                    "departure": {
                        "time": "2021-03-02T18:00:00+10:00",
                        "place": {
                            "type": "place",
                            "location": {
                                "lat": -27.4526753,
                                "lng": 153.0426484
                            },
                            "originalLocation": {
                                "lat": -27.45263,
                                "lng": 153.0423499
                            }
                        }
                    },
                    "arrival": {
                        "time": "2021-03-02T18:09:48+10:00",
                        "place": {
                            "type": "place",
                            "location": {
                                "lat": -27.4396845,
                                "lng": 153.0693942
                            },
                            "originalLocation": {
                                "lat": -27.4397501,
                                "lng": 153.06963
                            }
                        }
                    },
                    "transport": {
                        "mode": "car"
                    }
                }
            ]
        }
    ]
}

var totalTime
data = {
    "routes": [
        {
            "id": "f8b5d90a-d2b5-4149-b058-087c27e52fd0",
            "sections": [
                {
                    "id": "c16d58b7-7e2a-4ded-b8b7-96972d4ab0e4",
                    "type": "vehicle",
                    "departure": {
                        "time": "2021-03-02T18:00:00+10:00",
                        "place": {
                            "type": "place",
                            "location": {
                                "lat": -27.4526753,
                                "lng": 153.0426484
                            },
                            "originalLocation": {
                                "lat": -27.45263,
                                "lng": 153.0423499
                            }
                        }
                    },
                    "arrival": {
                        "time": "2021-03-02T18:09:48+10:00",
                        "place": {
                            "type": "place",
                            "location": {
                                "lat": -27.4396845,
                                "lng": 153.0693942
                            },
                            "originalLocation": {
                                "lat": -27.4397501,
                                "lng": 153.06963
                            }
                        }
                    },
                    "transport": {
                        "mode": "car"
                    }
                }
            ]
        }
    ]
}
$.each(data, function(i,value){
totalTime = value[0]['sections']['0']['arrival']['time'];
});
$('#results').text(totalTime);

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<label id = "results"></label>

【问题讨论】：

如果您创建自己的递归函数来搜索特定属性或值会更容易。检查this source 也this one 它可以帮助你。

标签： javascript jquery json

【解决方案1】：

您不需要$.each()。只需使用data.routes。

这个硬编码的[0] 索引假定您感兴趣的时间总是在第一条路线的第一部分。

data = {
  "routes": [{
    "id": "f8b5d90a-d2b5-4149-b058-087c27e52fd0",
    "sections": [{
      "id": "c16d58b7-7e2a-4ded-b8b7-96972d4ab0e4",
      "type": "vehicle",
      "departure": {
        "time": "2021-03-02T18:00:00+10:00",
        "place": {
          "type": "place",
          "location": {
            "lat": -27.4526753,
            "lng": 153.0426484
          },
          "originalLocation": {
            "lat": -27.45263,
            "lng": 153.0423499
          }
        }
      },
      "arrival": {
        "time": "2021-03-02T18:09:48+10:00",
        "place": {
          "type": "place",
          "location": {
            "lat": -27.4396845,
            "lng": 153.0693942
          },
          "originalLocation": {
            "lat": -27.4397501,
            "lng": 153.06963
          }
        }
      },
      "transport": {
        "mode": "car"
      }
    }]
  }]
}

var totalTime = data.routes[0].sections[0].arrival.time;

$('#results').text(totalTime);

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<label id="results"></label>

【讨论】：

【解决方案2】：

对于另一种防御性解决方案：

var totalTime
data = {
  "routes": [{
    "id": "f8b5d90a-d2b5-4149-b058-087c27e52fd0",
    "sections": [{
      "id": "c16d58b7-7e2a-4ded-b8b7-96972d4ab0e4",
      "type": "vehicle",
      "departure": {
        "time": "2021-03-02T18:00:00+10:00",
        "place": {
          "type": "place",
          "location": {
            "lat": -27.4526753,
            "lng": 153.0426484
          },
          "originalLocation": {
            "lat": -27.45263,
            "lng": 153.0423499
          }
        }
      },
      "arrival": {
        "time": "2021-03-02T18:09:48+10:00",
        "place": {
          "type": "place",
          "location": {
            "lat": -27.4396845,
            "lng": 153.0693942
          },
          "originalLocation": {
            "lat": -27.4397501,
            "lng": 153.06963
          }
        }
      },
      "transport": {
        "mode": "car"
      }
    }]
  }]
}

var totalTime = data && Array.isArray(data.routes) && Array.isArray(data.routes[0].sections) ? data.routes[0].sections[0].arrival.time : "";

$('body').text(totalTime);

&lt;script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"&gt;&lt;/script&gt;

这将确保如果没有返回数组或结果，您仍然可以得到一个可以依赖的值。

【讨论】：