Arrays 数组中的快速返回字符串
我试图从这个数组中获取一个随机名称,作为字符串而不是数字 即:数组通常返回一个随机数0到9,我希望它返回0到9表示的字符串,比如Preston或James,而不是数字本身 下面的代码已被破坏,但我希望它能让您看到我正在尝试做什么Arrays 数组中的快速返回字符串,arrays,macos,swift,Arrays,Macos,Swift,我试图从这个数组中获取一个随机名称,作为字符串而不是数字 即:数组通常返回一个随机数0到9,我希望它返回0到9表示的字符串,比如Preston或James,而不是数字本身 下面的代码已被破坏,但我希望它能让您看到我正在尝试做什么 var firstName : [String] = ["Preston", "Ally", "James", "Justin", "Dave", "Bacon", "Bossy", "Edward", "Edweird" ] var standardIde
var firstName : [String] = ["Preston", "Ally", "James", "Justin", "Dave", "Bacon", "Bossy", "Edward", "Edweird" ]
var standardIdent = "First Name:\(firstName[random(0...9)]) Last Name:\(lastName[random(0...5)]) \n Age:\(rand())"
println(standardIdent)
谢谢你的帮助 您应该使用
arc4random
如:
let firstRandom = Int(arc4random() % 10)
let secondRandom = Int(arc4random() % 6)
var standardIdent = "First Name:\(firstName[firstRandom]) Last Name:\(lastName[secondRandom]) \n Age:\(rand())"
您应该使用
arc4random
如:
let firstRandom = Int(arc4random() % 10)
let secondRandom = Int(arc4random() % 6)
var standardIdent = "First Name:\(firstName[firstRandom]) Last Name:\(lastName[secondRandom]) \n Age:\(rand())"
您不应将
arc4random()
与%
运算符一起使用。这就引出了一个新的问题
在Swift 4.2及更高版本中,应使用randomElement()
:
或者,如果阵列可能为空,请不要使用强制展开运算符,而是执行以下操作:
guard let randomFirstName = firstNames.randomElement() else {
print("array was empty")
return
}
在4.2之前的Swift版本中,您应该:
arc4random\u uniform
,而不是arc4random
,以消除模偏差您不应将
arc4random()
与%
运算符一起使用。这就引出了一个新的问题
在Swift 4.2及更高版本中,应使用randomElement()
:
或者,如果阵列可能为空,请不要使用强制展开运算符,而是执行以下操作:
guard let randomFirstName = firstNames.randomElement() else {
print("array was empty")
return
}
在4.2之前的Swift版本中,您应该:
arc4random\u uniform
,而不是arc4random
,以消除模偏差更好的方法是:使用
arc4random\u uniform
避免模偏差:
var firstName : [String] = ["Preston", "Ally", "James", "Justin", "Dave", "Bacon", "Bossy", "Edward", "Edweird" ]
var lastName : [String] = ["Miller", "Jones", "Jackson", "Smith"]
let firstRandom = Int(arc4random_uniform(UInt32(firstName.count)))
let secondRandom = Int(arc4random_uniform(UInt32(lastName.count)))
var standardIdent = "First Name:\(firstName[firstRandom]) Last Name:\(lastName[secondRandom]) \n Age:\(rand())"
更好的方法是:使用
arc4random\u uniform
避免模偏差:
var firstName : [String] = ["Preston", "Ally", "James", "Justin", "Dave", "Bacon", "Bossy", "Edward", "Edweird" ]
var lastName : [String] = ["Miller", "Jones", "Jackson", "Smith"]
let firstRandom = Int(arc4random_uniform(UInt32(firstName.count)))
let secondRandom = Int(arc4random_uniform(UInt32(lastName.count)))
var standardIdent = "First Name:\(firstName[firstRandom]) Last Name:\(lastName[secondRandom]) \n Age:\(rand())"