我如何创建一个将`width：100％`除以`th`的数字的JS函数？

Question

I've got this scrollable table from a website and it's pretty amazing, but the problem is it doesn't resize the headers equally automatically plus due to lack of knowledge on JS I have no Idea on how to do it. I believe it's gonna use a for based on the numbers of tr > th s then divide the 100% among them and set it as the width. Can you help me?

Beam me up Scotty!

PS: I want to fix it with JS, because I will make some changes in the future that will mess it up

 function removeClassName(elem, className) { elem.className = elem.className.replace(className, "").trim(); } function addCSSClass(elem, className) { removeClassName(elem, className); elem.className = (elem.className + " " + className).trim(); } String.prototype.trim = function() { return this.replace(/^\\s+|\\s+$/, ""); }; function stripedTable() { if (document.getElementById && document.getElementsByTagName) { var allTables = document.getElementsByTagName('table'); if (!allTables) { return; } for (var i = 0; i < allTables.length; i++) { if (allTables[i].className.match(/[\\w\\s ]*scrollTable[\\w\\s ]*/)) { var trs = allTables[i].getElementsByTagName("tr"); for (var j = 0; j < trs.length; j++) { removeClassName(trs[j], 'alternateRow'); addCSSClass(trs[j], 'normalRow'); } for (var k = 0; k < trs.length; k += 2) { removeClassName(trs[k], 'normalRow'); addCSSClass(trs[k], 'alternateRow'); } } } } } window.onload = function() { stripedTable(); }; 

 th { word-break: break-all; } body { background: #FFF; color: #000; font: normal normal 12px Verdana, Geneva, Arial, Helvetica, sans-serif; margin: 10px; padding: 0 } table, td, a { color: #000; font: normal normal 12px Verdana, Geneva, Arial, Helvetica, sans-serif } h1 { font: normal normal 18px Verdana, Geneva, Arial, Helvetica, sans-serif; margin: 0 0 5px 0 } h2 { font: normal normal 16px Verdana, Geneva, Arial, Helvetica, sans-serif; margin: 0 0 5px 0 } h3 { font: normal normal 13px Verdana, Geneva, Arial, Helvetica, sans-serif; color: #008000; margin: 0 0 15px 0 } /* end basic styling */ /* define height and width of scrollable area. Add 16px to width for scrollbar */ div.tableContainer { clear: both; border: 1px solid #963; height: 285px; overflow: auto; width: 100%; } /* Reset overflow value to hidden for all non-IE browsers. */ html>body div.tableContainer { overflow: hidden; width: 100%; height: 100%; } /* define width of the table. IE browsers only */ div.tableContainer table { float: left; width: 100%; } /* define width of table. Add 16px to width for scrollbar. */ /* All other non-IE browsers. */ html>body div.tableContainer table { width: 100%; } /* set table header to a fixed position. WinIE 6.x only */ /* In WinIE 6.x, any element with a position property set to relative and is a child of */ /* an element that has an overflow property set, the relative value translates into fixed. */ /* Ex: parent element DIV with a class of tableContainer has an overflow property set to auto */ thead.fixedHeader tr { position: relative } /* set THEAD element to have block level attributes. All other non-IE browsers */ /* this enables overflow to work on TBODY element. All other non-IE, non-Mozilla browsers */ html>body thead.fixedHeader tr { display: block } /* make the TH elements pretty */ thead.fixedHeader th { background: #C96; border-left: 1px solid #EB8; border-right: 1px solid #B74; border-top: 1px solid #EB8; font-weight: normal; padding: 4px 3px; text-align: left } /* make the A elements pretty. makes for nice clickable headers */ thead.fixedHeader a, thead.fixedHeader a:link, thead.fixedHeader a:visited { color: #FFF; display: block; text-decoration: none; width: 100% } /* make the A elements pretty. makes for nice clickable headers */ /* WARNING: swapping the background on hover may cause problems in WinIE 6.x */ thead.fixedHeader a:hover { color: #FFF; display: block; text-decoration: underline; width: 100% } /* define the table content to be scrollable */ /* set TBODY element to have block level attributes. All other non-IE browsers */ /* this enables overflow to work on TBODY element. All other non-IE, non-Mozilla browsers */ /* induced side effect is that child TDs no longer accept width: auto */ html>body tbody.scrollContent { display: block; height: 262px; overflow: auto; width: 100% } /* make TD elements pretty. Provide alternating classes for striping the table */ /* http://www.alistapart.com/articles/zebratables/ */ tbody.scrollContent td, tbody.scrollContent tr.normalRow td { background: #FFF; border-bottom: none; border-left: none; border-right: 1px solid #CCC; border-top: 1px solid #DDD; padding: 2px 3px 3px 4px } tbody.scrollContent tr.alternateRow td { background: #EEE; border-bottom: none; border-left: none; border-right: 1px solid #CCC; border-top: 1px solid #DDD; padding: 2px 3px 3px 4px } /* define width of TH elements: 1st, 2nd, and 3rd respectively. */ /* Add 16px to last TH for scrollbar padding. All other non-IE browsers. */ /* http://www.w3.org/TR/REC-CSS2/selector.html#adjacent-selectors */ /* define width of TD elements: 1st, 2nd, and 3rd respectively. */ /* All other non-IE browsers. */ /* http://www.w3.org/TR/REC-CSS2/selector.html#adjacent-selectors */ /*<----Cells*/ html>body tbody.scrollContent td { width: 100px; } html>body tbody.scrollContent td + td { width: 100px } html>body tbody.scrollContent td + td + td { width: 100px } /*<----Cells*/ /*<----Headers*/ html>body thead.fixedHeader th { width: 200px } html>body thead.fixedHeader th + th { width: 100px } html>body thead.fixedHeader th + th + th { width: 316px } /*<----Headers*/ 

 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <title>Pure CSS Scrollable Table with Fixed Header</title> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <meta http-equiv="language" content="en-us"> <style type="text/css"></style> </head> <body> <h1>Pure CSS Scrollable Table with Fixed Header</h1> <div id="tableContainer" class="tableContainer"> <table border="0" cellpadding="0" cellspacing="0" width="100%" class="scrollTable"> <thead class="fixedHeader"> <tr class="alternateRow"> <th><a href="#">Header 1ahjsgdhjagsdhjgahjsdghjasgdhjagshjdgahjsdghjagsdhj</a> </th> <th><a href="#">Header 2</a> </th> <th><a href="#">Header 3</a> </th> </tr> </thead> <tbody class="scrollContent"> <tr class="normalRow"> <td>Cell Content 1</td> <td>Cell Content 2</td> <td>Cell Content 3</td> </tr> <tr class="alternateRow"> <td>More Cell Content 1</td> <td>More Cell Content 2</td> <td>More Cell Content 3</td> </tr> </tbody> </table> </div> <div> <br> </div> </body><span class="gr__tooltip"><span class="gr__tooltip-content"></span><i class="gr__tooltip-logo"></i><span class="gr__triangle"></span></span> </html> 

Answer 1

What about using table-layout: fixed ?

table {
    table-layout: fixed;
} 

Answer 2

I agree that CSS may be a better option for this, but since you asked, couldn't you just do:

var th = document.getElementsByTagName("th");

for(var i=0; i<th.length; i++) {
    th[i].width = (100/th.length) + "%";    
}

Edited: Added Fiddle

Answer 3

To find the width of the whole table use table.offsetWidth , then cycle through your table like this:

    var table = document.getElementById("your-table-id");
    var w = table.offsetWidth; //total width of the table

    for (var y = 0; y < table.rows.length; y++){  // cycle through rows
        var row = table.rows[y];
        for (var x = 0; x < row.cells.length; x++) { // cycle through cells
            var cell = row.cells[x];
            cell.style.width = (w / row.cells.length) + "px"; // add 'px' for a unit
        }
    }

And here's a JSfiddle of it.