如何从Swift中的字典中获取键的值?
我有一本Swift字典。我想获得钥匙的价值。密钥方法的对象对我不起作用。如何获得字典键的值?
这是我的字典:
var companies = ["AAPL" : "Apple Inc", "GOOG" : "Google Inc", "AMZN" : "Amazon.com, Inc", "FB" : "Facebook Inc"]for name in companies.keys {
print(companies.objectForKey("AAPL"))
}
回答:
使用下标访问字典键的值。这将返回一个可选:
let apple: String? = companies["AAPL"]
要么
if let apple = companies["AAPL"] { // ...
}
您还可以枚举所有键和值:
var companies = ["AAPL" : "Apple Inc", "GOOG" : "Google Inc", "AMZN" : "Amazon.com, Inc", "FB" : "Facebook Inc"]for (key, value) in companies {
print("\(key) -> \(value)")
}
或枚举所有值:
for value in Array(companies.values) { print("\(value)")
}
以上是 如何从Swift中的字典中获取键的值? 的全部内容, 来源链接: utcz.com/qa/434150.html