How to set the image path of an element in css (src attribute)

CSS (Cascading Style Sheets) is an indispensable part of web design. It can add rich visual effects and layout to web pages, and can also make web pages present a unified style on different devices. When using CSS, one of the important issues is how to set the image path of the element (ie, the src attribute). Let’s introduce it in detail below.

1. Relative path

In Web development, the pictures and other resources required for the web page are usually stored in the same project folder, and the relative path is based on The path representation of the project folder. For example, if the web page file and image file are in the same folder, you can use a relative path to specify the image path.

For example:

background-image: url(./images/bg.jpg);

./ represents the current folder, images is the folder where pictures are stored, and bg.jpg is the name of the picture file. In this way, CSS can correctly read image resources and achieve style effects.

In addition, you can also use ../ to represent the upper-level folder, such as:

background-image: url(../images/bg.jpg);

In this way, CSS will search for the bg.jpg image in the images folder in the upper-level folder.

It should be noted that the accuracy of relative paths depends on the location of the current file. If the current file is in the root directory of the project folder, then you can use a relative path to represent the file path in the entire project folder; if the current file is in a subfolder of the project folder, then the relative path must refer to the relative path of the current file. The path to the project folder.

2. Absolute path

The absolute path is a path representation method based on the root directory of the website, which can completely determine the location of the image on the server. Using absolute paths can reduce the possibility of path errors, but is more complicated than relative paths.

For example:

background-image: url(/images/bg.jpg);

This path starts with "/" to indicate the path relative to the root directory of the website. CSS will directly go to the images folder in the root directory of the website to find the bg.jpg image.

It should be noted that using absolute paths will cause problems when crossing domains (jumping from one website to another) because you will no longer be able to access the files of the other website. At this time, you can use relative paths or reference images from other websites.

3. Use the Base tag

If there are multiple folders of the same level in the web page to store pictures, and you need to switch between these folders, you can use the Base tag. The Base tag is an element in HTML that tells the browser to use a path relative to the URL specified by the Base tag when parsing links and resources.

For example:

  <base>

This Base tag specifies the path to http://www.example.com/images/. At this time, the image path in CSS only needs to be expressed relative to this path. .

For example:

background-image: url(bg.jpg);

In this way, CSS will search for the bg.jpg image under http://www.example.com/images/.

Of course, after setting the Base tag, not only the image path in CSS will be affected, but also the links in HTML.

To sum up, when setting the image path, you need to choose a relative path or an absolute path according to the actual situation. Generally speaking, relative paths are used more because they are simpler and easier to maintain; and in special cases, using absolute paths or Base tags is also a good choice, which can effectively avoid path errors and cross-domain problems.

The above is the detailed content of How to set the image path of an element in css (src attribute). For more information, please follow other related articles on the PHP Chinese website!