Octal Literal (0o...) Regex Pattern
Matches modern octal numeric literals (0o prefix).
Pattern
^0o[0-7]+$Tested examples
0o7550o70o6440o0o87550O755Test it live
Live Regex TesterJS
0 matches/
/g
0o755 0o7 0o644
Use it in your language
Use it in
// JavaScript / Node.js
const regex = /^0o[0-7]+$/;
const value = "0o755";
const isMatch = regex.test(value);
console.log(isMatch); // true / false
// Extract all matches
const matches = value.match(/^0o[0-7]+$/g) || [];Tags
Frequently asked questions
How do I use the Octal Literal (0o...) regex pattern in JavaScript?
Wrap the pattern in slashes: const re = /^0o[0-7]+$/; — then call re.test(value) to check a single value, or value.match(re) to find matches. The "Use it in" snippets above give you the exact code for 9 languages.
Is this octal literal (0o...) regex production-ready?
Yes — every pattern in the library is tested against valid and invalid examples. Still, regex is one layer in a defense-in-depth strategy: pair it with server-side validation (e.g. Luhn for credit cards, mod-97 for IBAN, real DNS lookup for emails) for critical inputs.
Why does my pattern fail in another language?
Different regex engines (PCRE, Java, Python, Go's RE2) support slightly different syntax. The most common gotchas: lookbehinds (not in RE2), named groups syntax, and how backslashes need to be escaped inside string literals. The code snippets above already escape correctly for each language.
Can I edit this pattern and test it live?
Yes — use the live tester above. Type your test string and toggle flags (g, i, m, s, u, y) to see matches highlighted instantly, including capture groups.
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