求大佬看看我这个JS代码该如何更改。。。。。。。。。

document.write("

");

for (var x = 1; x <= 9; x++)

{

document.write("

");

for (var y = 9; x<=y; y--)

{
document.write("");

}  
document.write("</tr>"); 

}

document.write("

"+x+"*"+y+"="+x*y+"

");

我目前得到的效果是

我想要得到的效果是

for (var x = 1; x <= 9; x++){

        document.write("");

        for (var y = x; y<=9; y++){
              document.write(" ");
                          document.write(""+x+"*"+y+"="+x*y+"");  
        }  
        document.write("</br>"); 
    }

第二个for循环，你从1开始9结束啊

for(i = 1; i <= 9; i++) {
for(j = i; j <= 9; j++) {
document.write(i + "*" + j + "=" + j * i)
document.write("  ")
}
document.write("
")
}

 for(i = 1; i <= 9; i++) {
                for(j = i; j <= 9; j++) {
                    document.write(i + "*" + j + "=" + j * i)
                    document.write("&nbsp;&nbsp;")
                }
                document.write("<br/>")
            }

将这一循环条件for (var y = 9; x<=y; y--)改成for(var y=x;y<=9;y++)应该就可以了

    for (var x = 1; x <= 9; x++){
        document.write("");
        for (var y = x; y<=9; y++){
              document.write(" ");
                          document.write(""+x+"*"+y+"="+x*y+"");  
        }  
        document.write("</br>"); 
    }

第二个for循环写错了。分析：第二个for循环的值代表乘法中的第二个数字。从第一列看出，y的初始值与i相同。最后一个值都为9。所以，第二个for循环应该写成for( var y = i; y<= 9; y++)

/*具体央视只需要在元素标签上添加即可*/
/*table选择器*/
var multiplicationTable = document.getElementById("multiplication_table");

/*绘制table单元格*/
var multiplicationTable = "";
for(var i = 1; i <= 9; i ++){
multiplicationTableTd += "

";
for(var j = i; j <= 9; j ++){
multiplicationTableTd += "" + i + "*" + j + "";
}
multiplicationTableTd += "";
}

multiplicationTable.innerHTML = multiplicationTableTd;

    document.write("<table border='1'>"); 
    for (var x = 1; x <= 9; x++) {
        document.write("<tr>");
        for (var y = 9; y >= x; y--) {
            document.write("<td>" + x + "*" + y + "=" + x * y + "</td>");

        }
        document.write("</tr>");
    }
    document.write("</table>");

document.write("<tabel>"); for (var x = 1; x <= 9; x++) { document.write("<tr>"); for (var y=x; y<=9; y++) { document.write("&nbsp;"+x+"*"+y+"="+x*y+"&nbsp;"); document.write("&nbsp;"); } document.write("</tr>"); document.write("</br>"); } document.write("</tabel>");

测试通过，望采纳。

不确定是否正确：
for (var x = 1; x <= 9; x++){
document.write("");
for (var y = x; y<=9; y++){
document.write(" ");
document.write(""+x+"*"+y+"="+x*y+"");

}

document.write("");
}

第二个for循环写错了。应该是
for(j = i; j <= 9; j++) {
document.write(i + "*" + j + "=" + j * i)
document.write(" ")
}

for(i = 1; i <= 9; i++) {
for(j = i; j <= 9; j++) {
document.write(i + "*" + j + "=" + j * i)
document.write("  ")
}
document.write("
")
}