How to Validate an ABN in Code (Plus ACN, Postcodes, Phone Numbers and AEDT)
The ABN checksum with working code, ACN check digits, postcode leading zeros, E.164 mobiles, GST rounding and AEDT.
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Longer-form pieces on the things that catch people out: why large integers lose precision when they pass through JSON, what actually broke in MD5, why decoding a JWT proves nothing, and why the country code for Norway keeps breaking YAML config files.
The ABN checksum with working code, ACN check digits, postcode leading zeros, E.164 mobiles, GST rounding and AEDT.
Read ArticleThe repeated 1 a.m. hour, the 25-hour day, and the cron job that runs twice, plus the rules that prevent them.
Read ArticleWhy a SHA-256 of an email is still personal data, and when to use HMAC, tokenisation or aggregation instead.
Read ArticleFix Montréal turning into Montréal, sort French correctly, format fr-CA numbers, and validate postal codes.
Read ArticleEstructura del CFDI 4.0, conversión a JSON, UUID del timbre fiscal, validación de RFC y errores comunes.
Leer artículoLearn what JSON is, how it works, and why developers use it for APIs, apps, and structured data exchange.
Read ArticleLearn how to beautify messy JSON, validate structure, and work faster with formatted API data.
Read ArticleUnderstand validation errors, broken commas, quotes, brackets, and how to fix invalid JSON quickly.
Read ArticleA practical comparison of JSON and YAML for APIs, configuration files, and developer workflows.
Read ArticleTurn JSON arrays into spreadsheet-friendly CSV output for reporting, exports, and analysis.
Read ArticleConvert spreadsheet-style CSV data into clean JSON objects for APIs, apps, and testing.
Read ArticleLearn how to query nested JSON data, extract values faster, and inspect large API payloads with JSONPath.
Read ArticleUnderstand the difference between reading a JWT token and actually verifying whether it can be trusted.
Read ArticleHow Base64 works byte by byte, why output grows ~33%, the role of padding, and why it is not encryption.
Read ArticleThe UUID format, how version 4 is generated, why collisions are effectively impossible, and UUID vs GUID.
Read ArticleOne-way vs reversible: when to hash, when to encrypt, and the right tool for passwords, integrity, and secrecy.
Read ArticleMetacharacters, quantifiers, anchors, and groups, plus copy-ready patterns for email, URLs, dates, and more.
Read ArticleWhy length beats complexity, how passphrases and entropy work, and the habits that actually keep accounts safe.
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