Find special characters in string (Performance)

[Martin Lira]

Hello Guys,
I need to create a method that determines if certain characters like

 
if (str.indexOf(";") > -1 
   || str.indexOf("\'") > -1
   || str.indexOf("<") > -1
   || str.indexOf(">") > -1) 
{
foundChar = true;
} 
 
//OR
                int charAmount = in.length();
for (int i=0; i<charAmount; i++)
{
char c = in.charAt(i);
switch (c) {
case '<': foundChar = true; break;
case '>': foundChar = true; break;
case ';': foundChar = true; break;
}
 

Which of this two ways is better in performance? Or is there any better way?


Thanks
Martin
[ April 03, 2006: Message edited by: Martin Lira ]

[Alan Moore]

If no special characters are present, the first method will scan the whole string four times, while the second will only scan it once. Performance-wise, that's the only difference worth noticing, so you might as well go with the second method. But you're probably wasting your effort. Remember the three rules of optimization:

1. Don't do it.
2. Don't do it.
3. Before you do it, complete the app and profile it; the bottlenecks probably aren't where you expect them to be.