The sister directory path can be obtained in JavaScript using the ../ notation to move up one directory level in the file system.
Here's an example of how to get the sister directory path:
// Current directory: /home/user/project/homepage/
const sisterDir = '../aboutpage/';
In the example above, the current directory is /home/user/project/homepage/, and the sisterDir variable is assigned the path of the aboutpage directory in the same level of the file system.
If the current directory is deeper in the directory structure, then additional ../ notations may be necessary to reach the sister directory. For example:
// Current directory: /home/user/project/homepage/js/
const sisterDir = '../../aboutpage/';
In the second example, the current directory is /home/user/project/homepage/js/, and the sisterDir variable is assigned the path of the aboutpage directory, which is two levels up in the file system.
Note that the ../ notation can also be used multiple times to move up multiple directory levels, as demonstrated in the second example.