When you’re implementing a system that requires validation of Social Security Numbers (SSNs) in Java, regular expressions (regex) are an efficient tool to ensure the input matches the required format. Here’s how you can apply regex for SSN validation:
- Create a Regex Pattern: Construct a regex pattern to encapsulate the SSN structure. The structure is typically three digits, a hyphen, two digits, another hyphen, followed by four digits. For example:
XXX-XX-XXXX. - Pattern Specifications: Your pattern must exclude certain numbers such as 000 or 666 for the first three digits. It must also not allow the digits from 900 to 999. Similarly, the middle two digits should not be 00 and the last four digits should not be 0000.
- Compile and Match: Use the
Pattern.compilemethod to compile the regex pattern. Then, use theMatcherclass to test if the SSN string matches the pattern.
Pattern pattern = Pattern.compile("^(?!000|666)[0-8][0-9]{2}-(?!00)[0-9]{2}-(?!0000)[0-9]{4}$");
Matcher matcher = pattern.matcher(yourSSN); // replace yourSSN with the actual SSN string
boolean isValid = matcher.matches();
By adhering to the pattern specified, you can determine if a provided SSN has the correct format. Remember, this check only confirms the format, not whether the SSN is issued or exists.
