We should use composite character classes for the following reasons:
- To create new custom character classes from predefined Unicode blocks. For example, to match all the letters in an Arabic Unicode block, we can use the following:
[\p{InArabic}&&\p{L}]
- To avoid potentially slower lookahead or lookbehind patterns by using the intersection or subtraction operation on multiple character classes.
- To enhance the readability of the regular expression.
