🔸 TL;DR
Strings are a poor substitute for real types. If the data is a number, boolean, enum, date/time, money, or a composite/value object, model it as such. You’ll gain validation, discoverability, compiler checks, and clearer intent. 🧠✅
🔸 WHY STRINGS ARE A POOR SUBSTITUTE
▪️ Hard to validate at compile time (everything looks “valid”).
▪️ Encourage magic values (“YES”, “Y”, “true”, “1”…).
▪️ Fragile parsing & comparisons; easy i18n and casing bugs.
▪️ Hide domain meaning—future readers must guess intent.
▪️ Block IDE refactors and auto-completion. 🛠️
🔸 WHAT TO USE INSTEAD
▪️ Numeric? Use int, long, BigDecimal (for money/precision). 🔢
▪️ Boolean? Use boolean/Boolean. ✔️/❌
▪️ Choice set? Use an enum (Status.ACTIVE, not "active"). 🧩
▪️ Date/Time? Use LocalDate, Instant, ZonedDateTime. 📅
▪️ IDs with rules? Use typed value objects (Email, OrderId). 🏷️
▪️ Units? Use types that encode units (Duration, Period, domain classes). ⏱️
▪️ Aggregates? Create records/classes with named fields, not delimited strings. 📦
🔸 QUICK EXAMPLES (JAVA)
▪️ "true" ➜ boolean subscribed
▪️ "42" ➜ int retries
▪️ "ACTIVE" ➜ enum Status { ACTIVE, SUSPENDED }
▪️ "2025-11-09" ➜ LocalDate goLive
▪️ "john@acme.com" ➜ record Email(String value) { /* validate format */ }
▪️ "10:EUR" ➜ record Money(BigDecimal amount, Currency currency) {}
🔸 TAKEAWAYS
▪️ Model intent, not storage.
▪️ Let the type system catch bugs early.
▪️ Your future self (and teammates) will thank you. 🙏
▪️ Refactor strings into strong types as soon as you see rules or invariants emerging.
#CleanCode #Java #TypeSafety #Refactoring #SoftwareEngineering #DomainModeling #DDD #SpringBoot #BestPractices #CodeQuality
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