javascript - 我想在编辑表单上检查复选框，我在使用纯 javascript 添加表单上检查过

Question

我无法在编辑时检查复选框的逻辑（无数据库仅静态）请帮帮我

<td><input type="checkbox" name="subject" class="subject" value="maths">Maths
  <input type="checkbox" name="subject" class="subject" value="chemistry">Chemistry</td>
<button onclick="onEditPressed(' + index + ')">Edit</button><br/><button onclick="deleteTableRow('+ index + ')">Delete</button>

<script>
  function onEditPressed(index) {
    selectedIndex = index;
    var stuObj = localStorage.studentsRecord;
    studentsArray = JSON.parse(localStorage.studentsRecord);
    console.log(studentsArray);
    var stuObj = studentsArray[index];
    var checkboxes = stuObj.subject;
    document.getElementById("firstname").value = stuObj.firstname;
    document.getElementById("lastname").value = stuObj.lastname;
    document.getElementById("rollnum").value = stuObj.rollnum;
    var inputs = document.getElementsByClassName("subject");
    document.getElementById("submit").innerHTML = "Update";
  }
</script>

标签： javascript

Answer 1

使用查询选择器

var checkedBoxes = document.querySelectorAll('.subject:checked');

它将返回一组选定的复选框