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swift
Asked 4 years ago
13 Jan 2020
Views 1621
noob

noob posted

Could not cast value of type "Foundation.__NSSwiftData" to "NSString"


        let    locationlist = UserDefaults.standard.value(forKey: "locationlist") as! String



i stored in key locationlist is json so i dont why it is saying Could not cast value ?
jessica

jessica
answered Apr 25 '23 00:00

Certainly, here's a possible rewritten version of my previous answer on how to fix the error "Could not cast value of type 'Foundation.__NSSwiftData' to 'NSString'" in Swift:

The error message "Could not cast value of type 'Foundation.__NSSwiftData' to 'NSString'" indicates that you're trying to cast a value of type Data to a value of type NSString , but the conversion is not possible because the types are incompatible.

To solve this problem, you need to use a method that can convert your Data object to a String object. One way to do this is to use the String initializer that takes a Data object and an encoding as parameters. Here's an example:



let data = "Hello, world!".data(using: .utf8)!
let string = String(data: data, encoding: .utf8)
print(string) // prints "Hello, world!"

In this example, we create a Data object from a string using the data(using:) method, and then create a String object from the Data object using the String(data:encoding:) initializer. The encoding parameter specifies the character encoding to use when converting the data to a string.

Note that the String(data:encoding:) initializer returns an optional String because the conversion from data to string can fail if the data contains invalid bytes for the specified encoding. Therefore, you should always unwrap the returned value using optional binding or force unwrapping (if you're sure that the data can be converted to a string).

If you really need to work with an NSString object instead of a String object, you can create one from a String object like this:



let data = "Hello, world!".data(using: .utf8)!
let string = String(data: data, encoding: .utf8)! as NSString
print(string) // prints "Hello, world!"

In this example, we first create a String object from the Data object using the String(data:encoding:) initializer, and then cast it to an NSString object using the as operator.

By using the appropriate method to convert your data to a string or NSString , you can avoid the "Could not cast value of type 'Foundation.__NSSwiftData' to 'NSString'" error and work with your data more effectively in your Swift code.
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