Regular Expression to replace " {" with "(newline){" in xcode

You could try the following:

• In the Find box, type space \ { $
• In the Replace box, type control+q return {

control+q is needed to quote the return key. There’s no visual feedback for typing control+q return, so the only visible character in the replace box is the opening curly brace:

Although this answers your question, there’s (at least!) one problem: it won’t indent the opening curly brace, so something like

- (void)method {    for (obj in collection) {        NSLog(@"%@", obj);    }}

is converted to

- (void)method{    for (obj in collection){        NSLog(@"%@", obj);    }}

The menu item Edit > Format > Re-Indent will place the opening curly braces in the correct indentation tab but there might be non-desired side effects to your code style.

Edit: as commented in the other answer, you might want a regular expression that matches an arbitrary number of whitespaces surrounding the curly brace, e.g. \s*{\s*$

Just copy an example of needed replacement string (new line or else) from code to replacement box.

search for this \s\{ and replace with \n\{

Your editor needs to support regular expressions in both search and replace fields. If you can't use the \n in the replace dialog because it takes the string literally, try a option-enter followed by {, that works in most editors I tried.

• the \s is a space character (if therecould be more spaces you can use \s+)

note it has to be \s+ instead of \s* as someone fixed because indeed \s* also matches in case there is no space.

• the \{ needs the backslash because {
  needs to be escaped as it has anothermeaning in a regex
• the \n is for a newline

The best way however would be to reformat your code where you choose to have your { on a new line. Most editors allow you to set these options.

Another way is to use a code beautifier, you can google these online and some allow to change settings like that.