NSUserDefaults removeObjectForKey 与 setObject:nil [英] NSUserDefaults removeObjectForKey vs. setObject:nil

问题描述

下面两行等价吗?

1.[[NSUserDefaults standardUserDefaults] removeObjectForKey:@"example key"]

2.[[NSUserDefaults standardUserDefaults] setObject:nil forKey:@"example key"]

推荐答案

Swift 3.0

当我测试这个时，下面的答案不再是这种情况.当设置为 nil 时，结果是存储 NSCFData.可能是 NSNull 对象引用，但我不肯定.

The below answer is no longer the case when I tested this. When set to nil the result is NSCFData being stored. Possibly an NSNull object reference, but I am not positive.

要完全删除键的值，请使用 UserDefaults.standard.removeObject(forKey: "YourDefault")

To completely remove a value for a key use UserDefaults.standard.removeObject(forKey: "YourDefault")

我使用以下代码进行了测试:

I tested with the following code:

UserDefaults.standard.set(["a", "b", "c"], forKey: "MyDefaults")
print("Test A: My saved defaults \(UserDefaults.standard.object(forKey: "MyDefaults"))")

UserDefaults.standard.set(nil, forKey: "MyDefaults")
print("Test B: My defaults set to nil \(UserDefaults.standard.object(forKey: "MyDefaults"))")

UserDefaults.standard.removeObject(forKey: "MyDefaults")
print("Test C: My defaults removed \(UserDefaults.standard.object(forKey: "MyDefaults"))")

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