过滤数组
可以使用 filter(_:)
方法上 SequenceType
以创建包含满足给定谓词序列,其可以作为一个被提供的元素的新阵列闭合 。
例如,从 [Int]
中过滤偶数:
placeholderCopylet numbers = [22, 41, 23, 30]
let evenNumbers = numbers.filter { $0 % 2 == 0 }
print(evenNumbers) // [22, 30]
过滤 [Person]
,年龄小于 30 岁:
placeholderCopystruct Person {
var age : Int
}
let people = [Person(age: 22), Person(age: 41), Person(age: 23), Person(age: 30)]
let peopleYoungerThan30 = people.filter { $0.age < 30 }
print(peopleYoungerThan30) // [Person(age: 22), Person(age: 23)]