javascript delete selected

JavaScript is a commonly used programming language used for web development and the design of interactive user interfaces. There are many common operations in JavaScript programming, such as displaying prompt boxes, executing loops, conditional statements, etc. This article will focus on how to use JavaScript to delete selections.

JavaScript deletion is mainly used in form submission operations. When the user selects an item and clicks the "Delete" button, the item needs to be deleted from the form. In order to implement this function, you need to use JavaScript to write scripts to operate. The implementation methods and precautions will be introduced below.

1. JavaScript deletion selection method

Before using JavaScript to delete the selection, you first need to obtain the selected element. The element with the specified ID can be obtained through the getElementById method of the document object. For example, in the following HTML code, get the element with the ID "myList":

<ul id="myList">
  <li>选项1</li>
  <li>选项2</li>
  <li>选项3</li>
</ul>

Use the following JavaScript code to get the "Option 2" element:

var option = document.getElementById("myList").children[1];

Next, change the element with the following code Elements are deleted from the list:

option.remove();

2. Notes

When using JavaScript to delete the selection, you also need to pay attention to the following matters:

1. Confirm whether the element exists

Before deleting an element using JavaScript, you need to confirm whether the selected element exists. If the element does not exist, an exception will be thrown. In order to avoid this situation, you can use the following code to determine whether the element exists:

var option = document.getElementById("myList").children[1];

if (option) {
  option.remove();
}

2. Compatibility

Different browsers may have different support for JavaScript, and some browsers may not be able to correctly Execute delete method. In order to be compatible with different browsers, it is recommended to use the following code:

if (option.parentNode) {
  option.parentNode.removeChild(option);
}

This method can be executed normally in most browsers.

3. Operation confirmation

Before deleting an element, the user should also be asked to confirm whether the deletion operation is required. In order to achieve this confirmation, you can use the following code:

var confirmed = confirm("确定要删除吗？");

if (confirmed) {
  option.remove();
}

This code will pop up a prompt box to allow the user to confirm the deletion operation. If the user clicks the "OK" button, the delete operation will be performed.

3. Example Demonstration

The following is an example demonstration based on the above method:

<ul id="myList">
  <li>选项1</li>
  <li>选项2</li>
  <li>选项3</li>
</ul>

<button onclick="removeOption()">删除选中项</button>

<script>
function removeOption() {
  var option = document.getElementById(&quot;myList&quot;).children[1];
  var confirmed = confirm("确定要删除吗？");

  if (option && confirmed) {
    option.remove();
  }
}
</script>

In this example, when the user clicks the "Delete Selected Item" button, A confirmation prompt box will pop up. If the user clicks "OK", the "Option 2" element will be removed.

4. Summary

This article focuses on how to use JavaScript to delete selected elements. When operating, you need to pay attention to the existence, compatibility, and operation confirmation of elements. JavaScript deletion of selected elements is a common function in form submission operations. Mastering this skill will greatly improve the efficiency of web development.

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