The NSPredicate class is used to define logical conditions used to constrain a search either for a fetch or for in-memory filtering.
- when fetching objects, they arrive filtered from disk. This is used with Core Data
- when the predicate is used in memory, we filter content of arrays
You use predicates to represent logical conditions.
We can create predicates from:
- instances of NSComparisonPredicate, NSCompoundPredicate, and NSExpression
- a format string which is parsed by the class methods on NSPredicate
We're going to focus on the second approach: NSPredicate then feels like using SQL with your objects
Playground content authored by Diego Freniche. License: MIT. Please, don't remove this notice
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