Need to change Wi-Fi networks quickly? iOS 13 features a shortcut to make the switch without even unlocking your phone.
Historically, picking a new Wi-Fi network has required you to open the Settings app and tap Wi-Fi, forcing you to unlock your iPhone or switch away from what you were doing. In iOS 13, however, Apple added a better way to connect to a new Wi-Fi network
Open Control Center by swiping down from the upper-right corner on an iPhone X or later or an iPad; or up from the bottom on an earlier iPhone. Press and hold on the network settings card in the upper-left corner to expand it, and then press and hold on the Wi-Fi icon to reveal a list of Wi-Fi networks. Tap one to switch to it. You should be connected to the new Wi-Fi signal in moments.