我想替換數組中對象的值？

Question

我的數組中有一個時間戳，我已經從中刪除了 UTC 字母，我想用“新”時間戳替換舊時間戳（沒有 UTC） 也許有更簡單的方法來刪除？

所以我試圖用 .forEach 和 .map 循環我的數據試圖替換它，但仍然沒有弄清楚如何准確地這樣做。 我看過一堆關於這個的 Stackoverflow 線程，但還沒有找到我開始工作的解決方案......顯然遺漏了一些東西或寫錯了一些東西。

那么誰能指導我如何以最佳方式解決這個問題？

const data = [
  {
    timestamp: "2019-03-01 09:00:00UTC",
    url: "/blub.html",
    userid: "12345"
  },
  {
    timestamp: "2019-03-01 09:00:00UTC",
    url: "/cont.html ",
    userid: "12346"
  },
  {
    timestamp: "2019-03-01 10:00:00UTC ",
    url: "/cont.html ",
    userid: "12345"
  },
  {
    timestamp: "2019-03-01 10:30:00UTC",
    url: "/ho.html ",
    userid: "12347"
  }
];

console.log("data", data);
console.log("ex: first data object:", data[0]);


//loop through and grab the timestamp in each object and remove the UTC stamp
const GrabTimeStamp = () => {
  data.forEach(function (objects, index) {
   
    const timeStamp = objects.timestamp;
    const newTimeStamp = timeStamp.slice(0, 19);
    console.log("newTimeStamp:", newTimeStamp, index);

//next step to replace the old timestamp with newTimeStamp

  });
};
GrabTimeStamp()

Answer 1

您的代碼看起來不錯，只需重構該片段（使用forEach最佳方法）：

data.forEach((item, index) => {
   const timeStamp = item.timestamp;
   const newTimeStamp = timeStamp.slice(0, 19);
   item.timestamp = newTimeStamp; 
});

它應該工作。

Answer 2

你知道用“const”聲明的變量不能改變嗎？ 所以看起來你想在這里使用“var”。 最后 3 個字母可以通過“slice(0, -3)”刪除。

var data = [
  {
    timestamp: "2019-03-01 09:00:00UTC",
    url: "/blub.html",
    userid: "12345"
  },
  {
    timestamp: "2019-03-01 09:00:00UTC",
    url: "/cont.html ",
    userid: "12346"
  },
  {
    timestamp: "2019-03-01 10:00:00UTC",
    url: "/cont.html ",
    userid: "12345"
  },
  {
    timestamp: "2019-03-01 10:30:00UTC",
    url: "/ho.html ",
    userid: "12347"
  }
];

console.log("data", data);
console.log("ex: first data object:", data[0]);


//loop through and grab the timestamp in each object and remove the UTC stamp
var grabTimeStamp = () => {
  data.forEach(function (object, index) {
   
    var newTimeStamp = object.timestamp.slice(0, -3);
    console.log("newTimeStamp:", newTimeStamp, index);

    //next step to replace the old timestamp with newTimeStamp
    object.timestamp = newTimeStamp;
  });
};
grabTimeStamp();

由於您似乎對編碼還很陌生，因此我嘗試僅更改您代碼中的一些內容。 但是你的函數grabTimeStamp可以做得更短：

function removeTimestamp(data){
    data.foreach((item, index) => {
        item.timestamp = item.timestamp.slice(0, -3);
    });
}
removeTimestamp(data);