无法从for循环中获得预期结果

Question

我在for循环中遇到if语句时遇到麻烦，其中项目不适合h1下的放置，就像我期望的那样，这几乎就像if第一次被错过了而把事情搞砸了

这是一些示例代码和jsfiddle this

resultat

var jsonOut = [{
    "check": [{
        "name": "Singapore",
      },
      {
        "name": "SanFrancisco",
      },
      {
        "name": "Sydney",
      }
    ],
    "timestamp": 1535678338,
  },
  {
    "check": [{
        "name": "Singapore",
      },
      {
        "name": "SanFrancisco",
      },
      {
        "name": "Sydney",
      }
    ],
    "timestamp": 1535678338,
  },
  {
    "check": [{
        "name": "Singapore",
      },
      {
        "name": "SanFrancisco",
      },
      {
        "name": "Sydney",
      }
    ],
    "timestamp": 1535594440,
  },
  {
    "check": [{
        "name": "Singapore",
      },
      {
        "name": "SanFrancisco",
      },
      {
        "name": "Sydney",
      }
    ],
    "timestamp": 1535594440,
  },
]

var content = ''

var lastDate = 0

for (var i = 0; i < jsonOut.length; i++) {

  var testDate = new Date(jsonOut[i].timestamp * 1000);

  var contentNow = ''

  var ResultName = ''
  var h1marker = ''

  for (var j = 0; j < jsonOut[i].check.length; j++) {
    ResultName = ResultName + '' + jsonOut[i].check[j].name + '<br>'
    contentNow = testDate + '<br>' + ResultName
  }

  if (jsonOut[i].timestamp != lastDate) {
    h1marker = "<h1>" + testDate.getDate() + "</h1>"
    lastDate = jsonOut[i].timestamp
  }

  content = h1marker + contentNow + content

}

$("#tests").html(content)

Answer 1

您的if语句完全没有问题。您在此部分的代码

content = h1marker + contentNow + content

将新内容放在旧内容的前面，因此，每个日期的第二个条目都在标题“ 30”上方。

将其更改为content = content + h1marker + contentNow，如以下代码片段所示：

var jsonOut = [{
    "check": [{
        "name": "Singapore",
      },
      {
        "name": "SanFrancisco",
      },
      {
        "name": "Sydney",
      }
    ],
    "timestamp": 1535678338,
  },
  {
    "check": [{
        "name": "Singapore",
      },
      {
        "name": "SanFrancisco",
      },
      {
        "name": "Sydney",
      }
    ],
    "timestamp": 1535678338,
  },
  {
    "check": [{
        "name": "Singapore",
      },
      {
        "name": "SanFrancisco",
      },
      {
        "name": "Sydney",
      }
    ],
    "timestamp": 1535594440,
  },
  {
    "check": [{
        "name": "Singapore",
      },
      {
        "name": "SanFrancisco",
      },
      {
        "name": "Sydney",
      }
    ],
    "timestamp": 1535594440,
  },
]

var content = ''

var lastDate = 0

for (var i = 0; i < jsonOut.length; i++) {

  var testDate = new Date(jsonOut[i].timestamp * 1000);

  var contentNow = ''

  var ResultName = ''
  var h1marker = ''

  for (var j = 0; j < jsonOut[i].check.length; j++) {
    ResultName = ResultName + '' + jsonOut[i].check[j].name + '<br>'
    contentNow = testDate + '<br>' + ResultName
  }

  if (jsonOut[i].timestamp != lastDate) {
    h1marker = "<h1>" + testDate.getDate() + "</h1>"
    lastDate = jsonOut[i].timestamp
  }

  content = content + h1marker + contentNow

}

$("#tests").html(content)

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="tests">

</div>