我有以下尝试合并数组冗余元素的代码:
var items : [String] = ["hello", "world", "!", "hello"]
var mutableSet = Set<String>()
items.reduce(mutableSet, combine: { (set: Set<String>, element: String) in
return set.insert(element)
})
set.insert(element)
给我返回错误:Cannot use mutating member on immutable value: 'set' is a 'let' constant
。发生了什么问题,我应该怎样解决它?
let uniqueItems = Set(items)
更简单... - Martin RHashable
协议(这也意味着你的对象是Equatable
)。 - zneak