<|im_start|>user
How can I write a regex pattern to validate a US phone number format?<|im_end|>
<|im_start|>assistant
The regex pattern `^\(?\d{3}\)?[-.\s]?\d{3}[-.\s]?\d{4}$` is designed to match valid US phone numbers. It allows for optional parentheses around the area code, and it supports different separators such as dashes, dots, or spaces. Each segment of the phone number is validated: the area code consists of three digits, followed by three digits for the central office code, and finally four digits for the line number. This pattern ensures that users can recognize and adapt it for various formatting needs, all while maintaining clarity on how each part is structured.<|im_end|>

<|im_start|>user
How can I write a regex pattern to validate a US phone number format?<|im_end|>
<|im_start|>assistant
A regex pattern for phone numbers can be complex. Generally, phone numbers may contain digits and possibly some symbols. It's important to consider how numbers are formatted differently across regions, so a flexible approach might be needed. There are many examples online that you can refer to for more general regex patterns related to phone numbers.<|im_end|>

How can I write a regex pattern to validate a US phone number format?