当我使用 arc4random_uniform() 方法从数组中抓取元素时，数组中的同一元素通常会被多次抓取。我正在尝试使数组中的每个元素只被抓取一次。我尝试这样做的原因是UITableView中的多个单元格没有相同的文本。这是UITableView中单元格文本的数组：
var definitions = ["Used to carry the pharoah","Used to carry bodies as a ceremony","Had a flat deck to carry a farmer's treasure","Daily, it made a trip around the world to carry Ra","Towed by smaller boats, carrying heavy objects","Used for business and pleasure by officials/nobles","Carried most Egyptians and some goods"]
在我的viewDidLoad()方法中，我这样做是为了调用definitions的随机元素：
self.boats = [Boats(name: definitions[Int(arc4random_uniform(7))]),Boats(name: definitions[Int(arc4random_uniform(7))]),Boats(name: definitions[Int(arc4random_uniform(7))]),Boats(name: definitions[Int(arc4random_uniform(7))]),Boats(name: definitions[Int(arc4random_uniform(7))]),Boats(name: definitions[Int(arc4random_uniform(7))]),Boats(name: definitions[Int(arc4random_uniform(7))])]
如何更改我的代码，使两个元素不会在我的UITableView中显示两次？谢谢！
保留随机索引值的列表，如果后续随机索引在该列表中，则跳过它并生成另一个随机索引。