Re: [eclipse-dev] Beware of String#substring(...)

[Philippe P Mulet <philippe_mulet@xxxxxxxxxx>]

Along the same line, when creating String from some char[] fragment, you
should prefer doing:

  char[] original = ...;
  new String(original, start, length);

instead of:

  char[] original = ...;
  char[] fragment;
  System.arraycopy(original, 0, fragment = new char[length], start,
length);
  new String(fragment);

This saves the transient char[] allocation.




                                                                           
             Jerome                                                        
             Lanneluc/France/I                                             
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                                       [eclipse-dev] Beware of             
             03/25/2005 01:22          String#substring(...)               
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I just noticed that String#substring(...) shares the underlying char array.
So if you have a big string, take a substring of it, throw away the big
string, you will still hold on the big char array.
A simple way to solve this is to make a copy of the substring using the
String(String) constructor.

I saved 550KB in JDT Core by changing the following code:
      String simpleName =
fullyQualifiedName.substring(fullQualifiedName.lastIndexOf('.'));
to
      String simpleName = new
String(fullyQualifiedName.substring(fullQualifiedName.lastIndexOf('.')));

Jerome

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