在下表中：

<table>
    <thead>
        <tr>
            <th>Th1</th>
            <th colspan='2'>Th23</th>
            <th>Th4</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>Td1</td>
            <td>Td2</td>
            <td>Td3</td>
            <td>Td4</td>
       </tr>
    </tbody>
</table>

對(duì)于包含文本“Th23”的表格單元格,我想知道它下面有哪些單元格.在這種情況下,答案將是分別包含文本“Td2”和“Td3”的單元格.

是否有任何DOM屬性或內(nèi)置函數(shù)可以幫助進(jìn)行此類計(jì)算？

@Matt McDonald有一個(gè)更通用的解決方案.

這就是我最終得到的結(jié)果：

// get tbody cell(s) under thead cell (first arg)
// if rowIndex===undefined, get from all rows; otherwise, only that row index
// NOTE: does NOT work if any cell.rowSpan != 1
var columnCells = function( th, rowIndex ) {
    // get absolute column for th
    for( var absCol=0, i=0; true; i   ) {
            if( th.parentNode.cells[i] == th ) break;
            absCol  = th.parentNode.cells[i].colSpan;
    }
    // look in tBody for cells; all rows or rowIndex
    var tBody = th.parentNode.parentNode.nextSibling;
    var cells = [];
    for( var r=((rowIndex==undefined)?0:rowIndex); true; r   ) {
            if( rowIndex!==undefined && r>rowIndex ) break;
            if( rowIndex==undefined && r>=tBody.rows.length ) break;
            for( var c=0; true; c =tBody.rows[r].cells[c].colSpan ) {
                    if( c < absCol ) continue;
                    if( c >= absCol th.colSpan ) break;
                    cells.push(tBody.rows[r].cells[c]);
            }
    }
    return cells;
}

解決方法:

馬上,你需要做三件事：

>為表提供id屬性以便于選擇.
>為目標(biāo)單元格提供id屬性以便于選擇.
>選擇單元格的parentNode(行)

這三件事將使表格相關(guān)的計(jì)算更容易.

Next up是一個(gè)抓取指定單元格的偽屬性的函數(shù).在這種情況下,我們正在尋找它的“起始索引”(就列而言),它的“結(jié)束索引”(就列而言),以及它的“寬度”(結(jié)束 – 開始,也在列中).

從那里,您可以遍歷表的行并檢查哪些單元格位于開始和結(jié)束索引之間.

HTML：

<table id="foo">
    <colgroup span="1">
    <colgroup span="2">
    <colgroup span="1">
    <thead>
        <tr>
            <th>foo</th>
            <th id="example" colspan="2">bar</th>
            <th>baz</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>bing</td>
            <td>bang</td>
            <td>boom</td>
            <td>bong</td>
        </tr>
    </tbody>
</table>

JS(跟我一起)：

function getCellSpanProps(table, row, cell)
{
    var isRow = (function()
    {
        var i = 0, currentRow;
        for(i;i<table.rows.length;i  )
        {
            currentRow = table.rows[i];
            if(currentRow === row)
            {
                return true;
            }
            currentRow = null;
        }
        return false;
    }()), 
    cellHasCorrectParent, i = 0, 
    currentCell, colspanCount = 0,
    props;
    if(isRow)
    {
        cellHasCorrectParent = (function()
        {
            return cell.parentNode === row;
        }());
        if(cellHasCorrectParent)
        {
            for(i;i<row.cells.length;i  )
            {
                currentCell = row.cells[i];
                if(currentCell === cell)
                {
                    props = {"start": colspanCount, 
                    "end": colspanCount   cell.colSpan, 
                    "width": (colspanCount   cell.colSpan) - colspanCount};
                    break;
                }
                colspanCount  = currentCell.colSpan;
                currentCell = null;
            }
            row = null;
        }
        return props;
    }
}

function findCellsUnderColumn(table, props)
{
    var i = 0, j = 0, row, cell,
    colspanCount = 0, matches = [],
    blacklist = {"": true, "NaN": true, "null": true, "undefined": true, 
    "false": true};
    if(blacklist[props.start] || blacklist[props.end] || blacklist[props.width])
    {
        return false;
    }
    for(i;i<table.rows.length;i  )
    {
        row = table.rows[i];
        colspanCount = 0;
        for(j=0;j<row.cells.length;j  )
        {
            cell = row.cells[j];
            if(colspanCount >= props.start && colspanCount < props.end)
            {
                matches.push(cell);
            }
            colspanCount  = cell.colSpan;
            cell = null;
        }
        row = null;
    }
    return matches;
}

var table = document.getElementById("foo"), 
example = document.getElementById("example"),
targetRow = example.parentNode,
props = getCellSpanProps(table, targetRow, example),
matches = findCellsUnderColumn(table, props);
console.log(matches);

演示：http:///ohohew/edit#javascript,html

這將確定哪些單元格位于您要查找的特定列中(包括示例).您可以自定義功能以滿足您的需求,如果這不是您正在尋找的.