When editing text in OS X, you can quickly copy the formatting of one piece of text and apply it to another.
Move the cursor to the text containing the style that you want to copy. Enter Command-Option-C to copy. This will copy the formatting of text and not the text itself.
Select the text that you want to replace the text style. Enter Command-Option-V to paste the formatting.
You can use these commands in Apple apps, and in third party apps that implement this feature.