Shortcuts and Tips for Xcode and Mac

For Xcode

1. command + s = save
2. command + c = copy
3. command + v = paste
4. command + z = undo
5. shift + esc = show completion list
6. ctrl + . = show next completion

For Mac:

1. command + shift + 3 = capture full screen
2. command + shirt + 4 = capture part of a screen