Xcode隐藏功能

1. Switches between the .m and .h files.

Option(⌥）+ Command(⌘) + Up Arrow(↑)

View > Switch to Header/Source File

2. Quickly Help and definition.

Command(⌘) + Double-Click on a symbol: Jump to Definition of a symbol.

Option(⌥) + Double-Click on a symbol: Find Text in Documentation of a symbol. (Only works if you have they symbol's Doc Set installed.)

Control(⌃) + Command(⌘) + ? (While your cursor is in the symbol to look up)

双击的时候会打开单独的编辑器，单击的时候会在当前编辑器中打开。

3. Auto-completion 

Tab(⇥) OR Control (⌃) + /: Select the next auto-completion argument.

Shift(⇧) + Tab (⇥) OR Shift(⇧) + Control(⌃) + /: Select the previous auto-completion argument.

Escape(⎋): Shows the auto completion pop-up list.

4. Quickly jump to a Group in the Groups and Files pane

Control(⌃) + Option(⌥) + <First letter of a Group name>

5. Cycling between autocompletion choices

Control(⌃) + . :(Control-Period) after a word automatically accepts the first choice from the autocompletion menu.

Shift(⇧) + Control(⌃) + .: Cycles backwards between autocompletion choices.

6. Open quickly

Command(⌘)+ Shift(⇧) + O

File > Open Quickly...

7. Display a separator to organize methods in your source files

	#pragma mark -

8. Select overlapping items in Interface Builder

Control(⌃) + Shift(⇧) + Click on an object in Interface Builder to see a menu of all of the objects under the mouse.

9. Show TODO comment

 For example:

	// TODO: Some task that needs to be done.

Shows up in the drop down list of methods and functions so you can jump to it directly.

10. Double-click on the square brackets or parentheses to obtain bracket and parentheses matching.

部分来自 http://stackoverflow.com/questions/146297/hidden-features-of-xcode