需要一些帮助编码多个链式if语句

Question

我正在尝试在此表的单元格中返回一个值（下面提供的代码）：

<table id="gpa-calc-table" class="d_g d_gl" summary="List of grade items and their values">
  <tbody>
    <tr style="visibility:hidden;" class="fgskip">
      <td>&nbsp;</td>
      <td>&nbsp;</td>
      <td>&nbsp;</td>
      <td>&nbsp;</td>
    </tr>
    <tr class="gpa_calc_headings">
      <th scope="col" class="d_hch d_gl">Course Name</th>
      <th scope="col" class="d_hch d_gr" style="padding-left:0.1em;">Class Grade</th>
      <th scope="col" class="d_hch d_gr" style="padding-left:0.1em;">Grade Points</th>
      <th scope="col" class="d_hch d_gr" style="padding-left:0.1em;">Credit Units</th>
      <th scope="col" class="d_hch d_gr" style="padding-left:0.1em;">Total Grade Points</th>
    </tr>
    <tr class=" d_firstRow">

      <th scope="row" class="d_gt d_ich" id="gpa_calc_table_r1t">
        <label class="subject1" contenteditable=""><strong>First Class</strong></label>
      </th>
      <td class="d_gn d_gr d_gt">
        <label id="r1_cg" contenteditable="">91%<br></label>
      </td>

      <td class="d_gn d_gr d_gt">
        <label id="r1_gp" contenteditable="">
    <script>
function func1() {           
 var x = document.getElementById('r1_cg');
        var a = 49.9%;
        var b = 54.9%;
        var c = 59.9%;
        var d = 64.9%;
        var e = 69.9%;
        var f = 74.9%;
        var g = 79.9%;
        var h = 89.9%;
        if (x>h) {return 4.2};
        if (x>g) {return 4.0};
        if (x>f) {return 3.5}; 
        if (x>e) {return 3.0};
        if (x>d) {return 2.5};
        if (x>c) {return 2.0};
        if (x>b) {return 1.5};
        if (x>a) {return 1.0};}
    	
    </script></label>
      </td>
      <td class="d_gn d_gr d_gt">
        <label id="r1_cu" contenteditable="">0-5</label>
      </td>
      <td class="d_gn d_gr d_gt">
        <label id="r1_tgp" contenteditable="">CU*GP<br></label>
      </td>

    </tr>
    <tr class=" d_secondRow">

      <th scope="row" class="d_gt d_ich">
        <label class="subject2" contenteditable=""><strong>Second Class</strong></label>
      </th>
      <td class="d_gn d_gr d_gt">
        <label id="r2_cg" contenteditable="">0-100%</label>
      </td>

      <td class="d_gn d_gr d_gt">
        <label id="r2_gp" contenteditable="">0-4.2</label>
      </td>
      <td class="d_gn d_gr d_gt">
        <label id="r2_cu" contenteditable="">0-5</label>
      </td>
      <td class="d_gn d_gr d_gt">
        <label id="r2_tgp" contenteditable="">CU*GP</label>
      </td>

    </tr>

    <tr class=" d_thirdRow">

      <th scope="row" class="d_gt d_ich">
        <label class="subject3" contenteditable=""><strong>Third Class</strong></label>
      </th>
      <td class="d_gn d_gr d_gt">
        <label id="r3_cg" contenteditable="">0-100%</label>
      </td>

      <td class="d_gn d_gr d_gt">
        <label id="r3_gp" contenteditable="">0-4.2</label>
      </td>
      <td class="d_gn d_gr d_gt">
        <label id="r3_cu" contenteditable="">0-5</label>
      </td>
      <td class="d_gn d_gr d_gt">
        <label id="r3_tgp" contenteditable="">CU*GP</label>
      </td>

    </tr>
    <tr class=" d_fourthRow">

      <th scope="row" class="d_gt d_ich">
        <label class="subject4" contenteditable=""><strong>Fourth Class</strong></label>
      </th>
      <td class="d_gn d_gr d_gt">
        <label id="r4_cg" contenteditable="">0-100%</label>
      </td>

      <td class="d_gn d_gr d_gt">
        <label id="r4_gp" contenteditable="">0-4.2</label>
      </td>
      <td class="d_gn d_gr d_gt">
        <label id="r4_cu" contenteditable="">0-5</label>
      </td>
      <td class="d_gn d_gr d_gt">
        <label id="r4_tgp" contenteditable="">CU*GP</label>
      </td>

    </tr>
    <tr class=" d_fifthRow">

      <th scope="row" class="d_gt d_ich">
        <label class="subject5" contenteditable=""><strong>Fifth Class</strong></label>
      </th>
      <td class="d_gn d_gr d_gt">
        <label id="r5_cg" contenteditable="">0-100%</label>
      </td>

      <td class="d_gn d_gr d_gt">
        <label id="r5_gp" contenteditable="">0-4.2</label>
      </td>
      <td class="d_gn d_gr d_gt">
        <label id="r5_cu" contenteditable="">0-5</label>
      </td>
      <td class="d_gn d_gr d_gt">
        <label id="r5_tgp" contenteditable="">CU*GP</label>
      </td>

    </tr>
    <tr class=" d_sixthRow">

      <th scope="row" class="d_gt d_ich">
        <label class="subject6" contenteditable=""><b>Sixth Class</b><br></label>
      </th>

      <td class="d_gn d_gr d_gt">
        <label id="r6_cg" contenteditable="">0-100%</label>
      </td>
      <td class="d_gn d_gr d_gt">
        <label id="r6_gp" contenteditable="">0-4.2</label>
      </td>
      <td class="d_gn d_gr d_gt">
        <label id="r6_cu" contenteditable="">0-5</label>
      </td>
      <td class="d_gn d_gr d_gt">
        <label id="r6_tgp" contenteditable="">CU*GP</label>
      </td>
    </tr>

  </tbody>
</table>

此代码描述了表格中的一行（类似的应用程序将应用于其他行

`<tr class=" d_firstRow">

  <th scope="row" class="d_gt d_ich" id="gpa_calc_table_r1t">
    <label class="subject1" contenteditable=""><strong>First Class</strong></label>
  </th>
  <td class="d_gn d_gr d_gt">
    <label id="r1_cg" contenteditable="">91%<br></label>
  </td>

  <td class="d_gn d_gr d_gt">
    <label id="r1_gp" contenteditable="">
<script>
    function func1(){
    var x = document.getElementById('r1_cg');
    var a = 49.9%;
    var b = 54.9%;
    var c = 59.9%;
    var d = 64.9%;
    var e = 69.9%;
    var f = 74.9%;
    var g = 79.9%;
    var h = 89.9%;
    if (x>h) {return 4.2};
    if (x>g) {return 4.0};
    if (x>f) {return 3.5}; 
    if (x>e) {return 3.0};
    if (x>d) {return 2.5};
    if (x>c) {return 2.0};
    if (x>b) {return 1.5};
    if (x>a) {return 1.0};}

</script></label>
  </td>
  <td class="d_gn d_gr d_gt">
    <label id="r1_cu" contenteditable="">0-5</label>
  </td>
  <td class="d_gn d_gr d_gt">
    <label id="r1_tgp" contenteditable="">CU*GP<br></label>
  </td>

</tr>`

＆lt;脚本＆GT;因为如果等级在79.9％和89.9％之间，或者如果等级在59.9％和64.9％之间，那么我试图回报说4.0，等等。注意这是一个GPA计算器可能会有所帮助，我需要if（x> h）优先于链中较低的'if'函数等。任何帮助都表示赞赏。