Static vs Dynamic Typing: Differences and When to Use Each

Static vs Dynamic Typing

Static Typing

Types are determined at compile time; variable types cannot change

• Languages: Java, Go, Rust, TypeScript, C++
• ✅ Type errors caught at compile time; better IDE support
• ✅ Better runtime performance (types known at compile time)
• ❌ Requires explicit type declarations; slightly slower to write

Dynamic Typing

Types are determined at runtime; variables can hold any type

• Languages: Python, Ruby, JavaScript, PHP
• ✅ Faster development; flexible prototyping
• ❌ Type errors only discovered at runtime
• ❌ Harder to maintain in large codebases

Strong vs Weak Typing (different concept!)

• Strong: No implicit conversion of incompatible types (Python: "1" + 1 → TypeError)
• Weak: Allows implicit type coercion (JavaScript: "1" + 1 = "11")

Modern Trend: Convergence

• TypeScript = JavaScript + static types
• Python Type Hints + mypy for static analysis
• Dynamic languages moving toward "optional static typing"