我如何对结果进行四舍五入？

Question

<script >function sum() {    var txtFirstNumberValue = document.getElementById('studentenrolled').value;    var txtSecondNumberValue = document.getElementById('classsize').value;    var result = parseInt(txtFirstNumberValue) / parseInt(txtSecondNumberValue);    if (!isNaN(result)) {       document.getElementById('nooftut').value = result;    }}</script>         <tr>         <td><label for="studentenrolled">Student Enrolled</label>  </td>        <td> <input type="text" name="studentenrolled" id="studentenrolled"  value="<?php echo $row['studentenrolled']; ?> " /></td>         </tr>                       <tr>         <td><label for="classsize">Class Size</label>  </td>         <td> <input type="text" id="classsize"  onkeyup="sum();" /></td>         </tr>         <tr>        <td><label for="nooftut">No Of Tutorial</label>  </td>        <td> <input type="text" id="nooftut" disabled="disabled" /></td>        </tr> 如何在“nooftut”计算中向上或向下舍入结果：studentenrolled / class size = nooftut 由于 studentenrolled 是从数据库中提取的，我无法向上或向下舍入

Answer 1

尝试 Math.round()

function sum() {

    var txtFirstNumberValue = document.getElementById('studentenrolled').value;

    var txtSecondNumberValue = document.getElementById('classsize').value;

    var result = parseInt(txtFirstNumberValue) / parseInt(txtSecondNumberValue);

    if (!isNaN(result)) {

       document.getElementById('nooftut').value = Math.round(result);

    }

}

<tr>

   <td><label for="studentenrolled">Student Enrolled</label>  </td>

   <td> <input type="text" name="studentenrolled" id="studentenrolled" value=" " /></td>

</tr>              

<tr>

   <td><label for="classsize">Class Size</label>  </td>

   <td> <input type="text" id="classsize"  onkeyup="sum();" /></td>

</tr> 

<tr>

   <td><label for="nooftut">No Of Tutorial</label>  </td>

   <td> <input type="text" id="nooftut" disabled="disabled" /></td>

</tr>

Answer 2

+1.5 => +1.0 using Math.floor() (To round down)

-1.5 => -1.0 using Math.ceil() (To round up)

or just Math.round(0.9) => 1