Person.swift

struct Person {
    let name: String
    let age: Int
}

let persons = [
    Person(name: "Pera", age: 20),
    Person(name: "Mika", age: 30),
    Person(name: "Laza", age: 40)
]

// valid predicates
let namePredicate = NSPredicate(format: "name = %@", "Mika")
let agePredicate = NSPredicate(format: "age >= %@", 30)
let compoundPredicate = NSCompoundPredicate(andPredicateWithSubpredicates: [namePredicate, agePredicate])

// compiles but fails in runtime - wrong type
let wrongPredicate1 = NSPredicate(format: "age >= %@", "text")

// compiles but fails in runtime - wrong property
let wrongPredicate2 = NSPredicate(format: "password == %@", "123")

// finds two: (Mika, 30) and (Laza, 40)
_ = persons.filtered(using: agePredicate)

// finds one: (Mika, 30)
_ = persons.filtered(using: compoundPredicate)