Verify operation semantics

When implementing algorithms that process collections or use conditional logic, always verify the exact semantics of operations across different data structures.

For conditional operators like the Elvis operator (?:), be aware they may follow specific evaluation rules rather than intuitive reference semantics. For example, in SpEL, the Elvis operator checks for values that are non-null AND non-empty for Strings, which is more specific than general truthy/falsy rules from other languages:

// This will inject 25 if pop3.port is null OR an empty string
@Value("${pop3.port ?: 25}")
private int port;

For operations that process collections, verify which data structures are actually supported. Selection operations in SpEL work not just on lists and maps, but also on arrays and anything implementing java.lang.Iterable or java.util.Map interfaces:

// Works on lists, arrays, and any Iterable implementation
inventors.?[nationality == 'Serbian']

Understanding these semantics ensures your algorithms behave as expected across different data structures and prevents subtle bugs.