How can we programmatically change the brightness of the iPhone screen?

Question

How can I change the brightness of the screen programmatically using iPhone SDK?

Answer 1

UPDATE: For Swift 3

UIScreen.main.brightness = YourBrightnessValue

Here's the swift answer to perform this

UIScreen.mainScreen().brightness = YourBrightnessValue

YourBrightnessValue is a float between 0.0 and 1.0