The difference between insertbefore and before

The difference between insertbefore and before: 1. Usage; 2. Parameters; 3. Return value; 4. Compatibility; 5. Performance; 6. Selector; 7. Automatic creation of elements; 8. Error handling; 9. Cleaning; 10. Chain call; 11. Other differences. Detailed introduction: 1. Usage, insertBefore is a DOM method that can be called directly on any DOM element, before is a jQuery method that can only be called on jQuery objects; 2. Parameters, etc.

insertBefore and before are both methods used in JavaScript to manipulate DOM elements, but there are some important differences between them.

insertBefore(newNode, referenceNode) is a DOM method, which is used to insert a new node before the specified reference node. This method requires two parameters: new node (newNode) and reference node (referenceNode).

before(content, ...args) is a jQuery method that is used to insert content before the element. This method accepts two parameters: the content to be inserted (content) and other optional parameters.

The following is a detailed comparison of these two methods:

1. Usage:

insertBefore is a DOM method that can be called directly on any DOM element.

before is a jQuery method that can only be called on jQuery objects.

2. Parameters:

insertBefore accepts two parameters: the new node to be inserted and the reference node. The new node will be inserted before the reference node.

before accepts two parameters: the content to be inserted and other optional parameters. The content to be inserted can be an HTML string, a DOM element, or a jQuery object.

3. Return value:

insertBefore returns the inserted new node.

before returns the jQuery object on which it was called. This is very important for chained calls.

4. Compatibility:

insertBefore is part of the DOM standard, so it is available in all browsers.

before is a jQuery-specific method, so it can only be used in browsers that support jQuery.

5. Performance:

insertBefore is a native DOM operation, so its performance is usually better than jQuery's before method when processing a large number of DOM elements.

6. Selector:

insertBefore does not accept CSS selectors as parameters, it only accepts DOM elements or another node as a reference node.

before can accept CSS selectors as parameters, which allows us to easily insert content before the matching element.

7. Automatically create elements:

insertBefore will not automatically create elements. If the reference node does not exist, the new node will not be inserted.

before elements will be created automatically. If the target element does not exist, it will be created and the content inserted.

8. Error handling:

If the reference node does not exist when trying to use insertBefore, an error will be thrown.

When trying to use before, if the target element does not exist, it will automatically create the element and no error will be generated.

9. Cleaning:

insertBefore will not automatically clean or delete anything. You need to handle these things manually.

before will automatically clean up old content and replace it with new content. If you provide an HTML string, it will be converted to a jQuery object and inserted before the target element. If a DOM element or jQuery object is provided, it will be moved before the target element. If other parameters (such as text or functions) are provided, it will be converted to an HTML string and inserted before the target element. In all cases, older content is automatically deleted and replaced.

10. Chained calls:

insertBefore does not directly support chained calls. You need to call it twice in a separate statement to achieve the chaining effect. For example: element.parentNode.insertBefore(newElement, element);. However, you can call it twice in a single statement to simulate a chaining effect. For example: element.parentNode.insertBefore(newElement, element).parentNode.insertBefore(anotherElement, element);.

before directly supports chain calls. You can call it consecutively in a single statement to insert multiple elements or content. For example: element.before(content1).before(content2);. This inserts two contents in a row before the element.

11. Other differences:

insertBefore only accepts one reference node, while before can accept multiple content parameters and a reference node parameter (if provided). If you provide only a content parameter, it will be inserted before all matching elements. If you provide multiple content parameters, they will be inserted in order before the matching element. If you also provide a reference node parameter, the content will be inserted before the reference node (instead of before all matching elements).

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