title: Equivalent to exclamation mark for method names from ruby in other languages
body: <p>In Ruby, methods with side effects or methods that change the object passed as parameters have "!" as a postfix.</p>
  
  <p>For example:</p>
  
  <p><code>"SomeString".gsub!(/S/, "s")</code><br/>
  would be changing the String object, while<br/> 
  <code>"SomeString".gsub(/S/, "s")</code><br/>
  would work on a copy of the String object, and would not change the state of any objects outside of the method.</p>
  
  <p>I like this convention, and I'd like to use it when programming in other languages, too.</p>
  
  <p>My question:
  
  <li> Do real Ruby programmers (I'm not one;-)) actually use this convention? If not, why not?
  <li> Are there equivalent conventions for naming methods in Java, PHP, Perl, Cobol...?
  </p>