我是Swift的新手并且正在尝试。试图创建一个简单的字典值数组。这很粗糙,但我只是为字典对象复制了一小段代码,在每个部分中更改了值,然后将四个中的每一个都添加到数组中。
当我打印数组时,我发现它包含最后一个字典对象的四个版本。怎么可能?我原本期望数组有四个字典对象,即每个对象中的一个。
func countDown() {
let dict: NSMutableDictionary = [:]
let enduroArrayFile = NSMutableArray()
dict.setObject(1, forKey: "SectionDistance")
dict.setObject("S", forKey: "Direction")
dict.setObject(0, forKey: "ArrivalTime")
dict.setObject(0, forKey: "AverageSpeed")
//saving dictionary to array
enduroArrayFile.addObject(dict)
dict.setObject(1.2, forKey: "SectionDistance")
dict.setObject("S", forKey: "Direction")
dict.setObject(0, forKey: "ArrivalTime")
dict.setObject(0, forKey: "AverageSpeed")
//saving dictionary to array
enduroArrayFile.addObject(dict)
dict.setObject(2, forKey: "SectionDistance")
dict.setObject("R", forKey: "Direction")
dict.setObject(0, forKey: "ArrivalTime")
dict.setObject(0, forKey: "AverageSpeed")
//saving dictionary to array
enduroArrayFile.addObject(dict)
dict.setObject(2.1, forKey: "SectionDistance")
dict.setObject("S", forKey: "Direction")
dict.setObject(0, forKey: "ArrivalTime")
dict.setObject(0, forKey: "AverageSpeed")
//saving dictionary to array
enduroArrayFile.addObject(dict)
print (enduroArrayFile)
}
输出
(
{
ArrivalTime = 0;
AverageSpeed = 0;
Direction = S;
SectionDistance = "2.1";
},
{
ArrivalTime = 0;
AverageSpeed = 0;
Direction = S;
SectionDistance = "2.1";
},
{
ArrivalTime = 0;
AverageSpeed = 0;
Direction = S;
SectionDistance = "2.1";
},
{
ArrivalTime = 0;
AverageSpeed = 0;
Direction = S;
SectionDistance = "2.1";
}
)
答案 0 :(得分:4)
你错误地重复使用dict
。您需要每次都创建一个新实例。
func countDown() {
let enduroArrayFile = NSMutableArray()
var dict: NSMutableDictionary = [:]
dict.setObject(1, forKey: "SectionDistance")
dict.setObject("S", forKey: "Direction")
dict.setObject(0, forKey: "ArrivalTime")
dict.setObject(0, forKey: "AverageSpeed")
//saving dictionary to array
enduroArrayFile.addObject(dict)
dict = [:]
dict.setObject(1.2, forKey: "SectionDistance")
dict.setObject("S", forKey: "Direction")
dict.setObject(0, forKey: "ArrivalTime")
dict.setObject(0, forKey: "AverageSpeed")
//saving dictionary to array
enduroArrayFile.addObject(dict)
dict = [:]
dict.setObject(2, forKey: "SectionDistance")
dict.setObject("R", forKey: "Direction")
dict.setObject(0, forKey: "ArrivalTime")
dict.setObject(0, forKey: "AverageSpeed")
//saving dictionary to array
enduroArrayFile.addObject(dict)
dict = [:]
dict.setObject(2.1, forKey: "SectionDistance")
dict.setObject("S", forKey: "Direction")
dict.setObject(0, forKey: "ArrivalTime")
dict.setObject(0, forKey: "AverageSpeed")
//saving dictionary to array
enduroArrayFile.addObject(dict)
print (enduroArrayFile)
}
我不太了解Swift,所以我的语法错了。