Re: indexOf

From:
Roedy Green <see_website@mindprod.com.invalid>
Newsgroups:
comp.lang.java.help
Date:
Thu, 21 Feb 2008 16:08:05 GMT
Message-ID:
<j38rr35lvmmilrcp53uicr4d3o117cgoer@4ax.com>
On Thu, 21 Feb 2008 06:17:28 -0500, "Jean Pierre Daviau"
<Once@WasEno.ugh> wrote, quoted or indirectly quoted someone who said
:

public static boolean checkExtensions(String tmp){

String ext[] = {"html", "htm", "lnk", "mov", "avi", "psd", "ai",
"ps", "tif", "nws", "txt", "raw", "pdf"};

for (int i=0; i<ext.length ;i++ )
{
     if(tmp.indexOf(ext[i]) != -1){
      return true;
     }
}
return false;
}


Some improvements:

1. your list of extensions can be static final. No need to build the
list on every call.

2. you can use for:each syntax on your loop. see
http://mindprod.com/jgloss/jcheat.html

3. I would compare >=0 rather than != -1. Comparing against 0 is
faster than against other integers. It also guards against a freaky
-2. It also more conventional, and hence easier for other programmers
to read.

4. you don't really want indexOf. file "external.doc" would pass
your "ext" check. You want endsWith including a dot.

See http://mindprod.com/products1.html#FILTER. It has
 source code for a extensions filter that does just this for you.
--

Roedy Green Canadian Mind Products
The Java Glossary
http://mindprod.com

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