对象数组的 CSV 格式，总计运行

Question

编辑：我该怎么做：

    tickets = [ 
{ date: "Jan 05,2016", time: "08:19 AM", name: "Bernie Sanders" },
{ date: "Jan 05,2016", time: "09:29 AM", name: "Donald Trump" },
{ date: "Jan 05,2016", time: "09:31 AM", name: "Donald Trump" },
{ date: "Jan 05,2016", time: "09:34 AM", name: "Donald Trump" },
{ date: "Jan 05,2016", time: "09:34 AM", name: "Bernie Sanders" },
{ date: "Jan 05,2016", time: "09:07 AM", name: "Mike Huckabee"}
];

    ...

对此：

tickets = [ 
{ date: "Jan 05,2016", time: "08:19 AM", name: "Bernie Sanders", total: 1 },
{ date: "Jan 05,2016", time: "09:29 AM", name: "Donald Trump", total: 1 },
{ date: "Jan 05,2016", time: "09:31 AM", name: "Donald Trump", total: 2 },
{ date: "Jan 05,2016", time: "09:34 AM", name: "Donald Trump", total: 3 },
{ date: "Jan 05,2016", time: "09:34 AM", name: "Bernie Sanders", total: 2 },
{ date: "Jan 05,2016", time: "09:07 AM", name: "Mike Huckabee", total: 1}
]

我查看了处理对象和数组的流行库。例如，underscore.js、lodash.js、lazy.js。我找不到任何可以做到这一点的东西

Answer 1

不是我的，但这就是你要找的：

// Source: http://www.bennadel.com/blog/1504-Ask-Ben-Parsing-CSV-Strings-With-Javascript-Exec-Regular-Expression-Command.htm
// This will parse a delimited string into an array of
// arrays. The default delimiter is the comma, but this
// can be overriden in the second argument.

function CSVToArray(strData, strDelimiter) {
    // Check to see if the delimiter is defined. If not,
    // then default to comma.
    strDelimiter = (strDelimiter || ",");
    // Create a regular expression to parse the CSV values.
    var objPattern = new RegExp((
    // Delimiters.
    "(\" + strDelimiter + "|\r?\n|\r|^)" +
    // Quoted fields.
    "(?:\"([^\"]*(?:\"\"[^\"]*)*)\"|" +
    // Standard fields.
    "([^\"\" + strDelimiter + "\r\n]*))"), "gi");
    // Create an array to hold our data. Give the array
    // a default empty first row.
    var arrData = [[]];
    // Create an array to hold our individual pattern
    // matching groups.
    var arrMatches = null;
    // Keep looping over the regular expression matches
    // until we can no longer find a match.
    while (arrMatches = objPattern.exec(strData)) {
        // Get the delimiter that was found.
        var strMatchedDelimiter = arrMatches[1];
        // Check to see if the given delimiter has a length
        // (is not the start of string) and if it matches
        // field delimiter. If id does not, then we know
        // that this delimiter is a row delimiter.
        if (strMatchedDelimiter.length && (strMatchedDelimiter != strDelimiter)) {
            // Since we have reached a new row of data,
            // add an empty row to our data array.
            arrData.push([]);
        }
        // Now that we have our delimiter out of the way,
        // let's check to see which kind of value we
        // captured (quoted or unquoted).
        if (arrMatches[2]) {
            // We found a quoted value. When we capture
            // this value, unescape any double quotes.
            var strMatchedValue = arrMatches[2].replace(
            new RegExp("\"\"", "g"), "\"");
        } else {
            // We found a non-quoted value.
            var strMatchedValue = arrMatches[3];
        }
        // Now that we have our value string, let's add
        // it to the data array.
        arrData[arrData.length - 1].push(strMatchedValue);
    }
    // Return the parsed data.
    return (arrData);
}

function CSV2JSON(csv) {
    var array = CSVToArray(csv);
    var objArray = [];
    for (var i = 1; i < array.length; i++) {
        objArray[i - 1] = {};
        for (var k = 0; k < array[0].length && k < array[i].length; k++) {
            var key = array[0][k];
            objArray[i - 1][key] = array[i][k]
        }
    }

    var json = JSON.stringify(objArray);
    var str = json.replace(/},/g, "},\r\n");

    return str;
}

JSFiddle 在这里：

http://jsfiddle.net/sturtevant/AZFvQ/

Answer 2

假设您想获得某个人的条目总数，您可以使用 underscore.js groupBy() and reduce() 函数

Answer 3

假设您不需要支持旧版浏览器，vanillaJS 拥有您需要的一切：

tickets = [ 
  { date: "Jan 05,2016", time: "08:19 AM", name: "Bernie Sanders" },
  { date: "Jan 05,2016", time: "09:29 AM", name: "Donald Trump" },
  { date: "Jan 05,2016", time: "09:31 AM", name: "Donald Trump" },
  { date: "Jan 05,2016", time: "09:34 AM", name: "Donald Trump" },
  { date: "Jan 05,2016", time: "09:34 AM", name: "Bernie Sanders" },
  { date: "Jan 05,2016", time: "09:07 AM", name: "Mike Huckabee"}
];

var x = document.getElementById('x');

var runningTotals = {};

var addTotalToTicket = function(ticket){
  if ( ! (ticket.name in runningTotals ) ) {
    runningTotals[ticket.name] = 0;  
  }
  runningTotals[ticket.name]++;
  ticket.votes = runningTotals[ticket.name];
  return ticket;
};

var ticketsWithTotals = tickets.map(addTotalToTicket);

x.innerHTML = JSON.stringify(ticketsWithTotals,null,"  ");

pre {
  background-color: #ded;
}

<pre><code id="x"></code></pre>

对象数组的 CSV 格式，总计运行

CSV format to object array with running total

javascript

object

underscore.js

lodash

lazy.js

对象数组的 CSV 格式，总计 运行

CSV format to object array with running total

javascript

object

underscore.js

lodash

lazy.js

对象数组的 CSV 格式，总计运行