我创建了以下js函数

function csvDecode(csvRecordsList)
{
    var cel;
    var chk;
    var chkACB;
    var chkAF;
    var chkAMR;
    var chkAN;
    var csvField;
    var csvFieldLen;
    var csvFieldsList;
    var csvRow;
    var csvRowLen = csvRecordsList.length;
    var frag = document.createDocumentFragment();
    var injectFragInTbody = function () {tblbody.replaceChild(frag, tblbody.firstElementChild);};
    var isFirstRec;
    var len;
    var newEmbtyRow;
    var objCells;
    var parReEx = new RegExp(myCsvParag, 'ig');
    var tblbody;
    var tblCount = 0;
    var tgtTblBodyID;

    for (csvRow = 0; csvRow < csvRowLen; csvRow++)
    {
        if (csvRecordsList[csvRow].startsWith(myTBodySep))
        {
            if (frag.childElementCount > 0)
            {
                injectFragInTbody();
            }
            tgtTblBodyID = csvRecordsList[csvRow].split(myTBodySep)[1];
            newEmbtyRow = getNewEmptyRow(tgtTblBodyID);
            objCells = newEmbtyRow.cells;
            len = newEmbtyRow.querySelectorAll('input')[0].parentNode.cellIndex; // Finds the cell index where is placed the first input (Check-box or button)

            tblbody = getElById(tgtTblBodyID);
            chkAF = toBool(tblbody.dataset.acceptfiles);
            chkACB = toBool(tblbody.dataset.acceptcheckboxes) ;
            chkAN = toBool(tblbody.dataset.acceptmultiplerows) ;
            tblCount++;
            continue;
        }

        csvRecordsList[csvRow] = csvRecordsList[csvRow].replace(parReEx, myInnerHTMLParag); // Replaces all the paragraph symbols ¶ used into the db.csv file with the tag <br> needed into the HTML content of table cells, this way will be possible to use line breaks into table cells
        csvFieldsList = csvRecordsList[csvRow].split(myEndOfFld);

        csvFieldLen = csvFieldsList.length;
        for (csvField = 0; csvField < csvFieldLen; csvField++)
        {
            cel = chkAN ? csvField + 1 : csvField;
            if (chkAF && cel === 1) {objCells[cel].innerHTML =  makeFileLink(csvFieldsList[csvField]);} 
            else if (chkACB && cel === len) {objCells[cel].firstChild.checked = toBool(csvFieldsList[csvField]);}
            else {objCells[cel].innerHTML = csvFieldsList[csvField];}
        }
        frag.appendChild(newEmbtyRow.cloneNode(true));
    }
    injectFragInTbody();

    var recNum = getElById(tgtTblBodyID).childElementCount;
    customizeHtmlTitle();
    return csvRow - tblCount + ' (di cui '+ recNum + ' record di documenti)';
}

function makeFileLink(fname)
{
    return ['<a href="', dirDocSan, fname, '" target="', previewWinName, '" title="Apri il file allegato: ', fname, '" >', fname, '</a>'].join('');
}

data field content 1|data field content 2|data field content 3|etc...

csvRecordsList[csvRow].replace(par, myInnerHTMLParag)

最佳答案

事实上，使用 DOM 操作构建表比简单的要慢得多 innerHTML更新表格元素。

如果您尝试重写代码以准备一个 html 字符串并将其放入表格的 innerHTML 中，您将看到显着的性能提升。

浏览器经过优化以解析 text/html他们从服务器收到，因为这是他们的主要目的。通过 JS 的 DOM 操作是次要的，所以它们没有那么优化。

我为你做了一个简单的基准测试。

让我们制作一个 300x300 的表格并用“A”填充 90000 个单元格。
有两个功能。

第一个是代码的简化变体 使用 DOM methods :

var table = document.querySelector('table tbody');
var cells_in_row = 300, rows_total = 300;

var start = performance.now();
fill_table_1();
console.log('using DOM methods: ' + (performance.now() - start).toFixed(2) + 'ms');

table.innerHTML = '<tbody></tbody>';


function fill_table_1() {
  var frag = document.createDocumentFragment();

  var injectFragInTbody = function() {
    table.replaceChild(frag, table.firstElementChild)
  }

  var getNewEmptyRow = function() {
    var row = table.firstElementChild;
    if (!row) {
      row = table.insertRow(0);
      for (var c = 0; c < cells_in_row; c++) row.insertCell(c);
    }
    return row.cloneNode(true);
  }

  for (var r = 0; r < rows_total; r++) {
    var new_row = getNewEmptyRow();
    var cells = new_row.cells;
    for (var c = 0; c < cells_in_row; c++) cells[c].innerHTML = 'A';
    frag.appendChild(new_row.cloneNode(true));
  }
  injectFragInTbody();
  return false;
}

<table><tbody></tbody></table>

var table = document.querySelector('table tbody');
var cells_in_row = 300, rows_total = 300;

var start = performance.now();
fill_table_2();
console.log('setting innerHTML: ' + (performance.now() - start).toFixed(2) + 'ms');

table.innerHTML = '<tbody></tbody>';

function fill_table_2() {// setting innerHTML
  var html = '';
  for (var r = 0; r < rows_total; r++) {
    html += '<tr>';
    for (var c = 0; c < cells_in_row; c++) html += '<td>A</td>';
    html += '</tr>';
  }
  table.innerHTML = html;
  return false;
}

<table><tbody></tbody></table>

关于Javascript 性能优化，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/48699650/