What is method swizzling in Swift and when would you use it?

Method swizzling allows changing method implementations at runtime, primarily used for debugging and testing.\n\n• **Implementation:**\n\nimport ObjectiveC\n\nextension UIViewController {\n @ func swizzled_viewDidLoad() {\n print("View loaded")\n swizzled_viewDidLoad() // Calls original\n }\n \n func swizzleViewDidLoad() {\n let originalSelector = #selector(viewDidLoad)\n let swizzledSelector = #selector(swizzled_viewDidLoad)\n \n let originalMethod = class_getInstanceMethod(self, originalSelector),\n let swizzledMethod = class_getInstanceMethod(self, swizzledSelector) else {\n return\n }\n \n method_exchangeImplementations(originalMethod, swizzledMethod)\n }\n}\n\n\n• **Use Cases:**\n• Analytics tracking\n• Debugging and logging\n• Testing and mocking\n• Third-party library integration\n\n• **Cautions:**\n• Can make code hard to debug\n• Should be used sparingly\n• Requires @objc compatibility