Is there any way to enable Xcode's Check Spelling While Typing option on every Xcode project and file by default?
Currently, I have to set this option on each file, and the option gets reset after closing Xcode.
Option in question (Edit>Format>Spelling and Grammar>Check Spelling While Typing):
Yes, you can change the default setting in System Preferences, then Language & Region and in Keyboard Preferences (Text tab) you can enable/disable Correct spelling automatically option.
Tested under OS X - El Capitan.
See also: Turn off Spell Checking permanently
While I don't know a way to do this automatically, you can make choosing this option a little faster by setting up a shortcut in Sys Prefs->Keyboard->Shortcuts. Click App Shortcuts then the Plus button to add a keyboard shortcut that triggers this menu item.
来源：https://stackoverflow.com/questions/35463530/enable-xcodes-check-spelling-while-typing-option-by-default