<!--
{
  "availability" : [
    "iOS: 2.0.0 -",
    "iPadOS: 2.0.0 -",
    "macCatalyst: 13.0.0 -",
    "macOS: 10.0.0 -",
    "tvOS: 9.0.0 -",
    "visionOS: 1.0.0 -",
    "watchOS: 2.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "Foundation",
  "identifier" : "/documentation/Foundation/NSKeyedUnarchiver/decodeFloat(forKey:)",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Method",
  "symbol" : {
    "kind" : "Instance Method",
    "modules" : [
      "Foundation"
    ],
    "preciseIdentifier" : "c:objc(cs)NSKeyedUnarchiver(im)decodeFloatForKey:"
  },
  "title" : "decodeFloat(forKey:)"
}
-->

# decodeFloat(forKey:)

Decodes a single-precision floating-point value associated with a given key.

```
func decodeFloat(forKey key: String) -> Float
```

## Parameters

`key`

A key in the archive within the current decoding scope. `key` must not be `nil`.

## Return Value

The single-precision floating-point value associated with the key `key`. Returns `0.0` if `key` does not exist.

## Discussion

If the archived value was encoded as double precision, the type is coerced, loosing precision. If the archived value is too large for single precision, the method raises an `NSRangeException`.

## See Also

[`encode(_:forKey:)`](/documentation/Foundation/NSKeyedArchiver/encode(_:forKey:)-67rcs)

Encodes a given `float` value and associates it with a key.

[`encode(_:forKey:)`](/documentation/Foundation/NSKeyedArchiver/encode(_:forKey:)-1mkfl)

Encodes a given `double` value and associates it with a key.


---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)