Question

Just wondering if anyone knew off the top of their heads if there was much difference in doing the following:

String wibble = '<blah> blah blah </blah>.... <wibble> blah wibble blah </wibble> some more test here';  int i = wibble.lastIndexOf('>'); int j = wibble.lastIndexOf('>'); 

Answer 1

Opinions are great but data are better. I wrote a quick benchmark:

Test Code

public static void main(String[] args) {   System.out.println('Starting perfo test');    final long NUM_TESTS = 100000000L;    String wibble = '<blah> blah blah </blah>.... <wibble>'                 + ' blah wibble blah </wibble> some more test here';   int x = -1;   Stopwatch sw = new Stopwatch();    System.out.println('--perfo test with ' + NUM_TESTS + ' iterations--');    sw.start();   for(long i = 0; i < NUM_TESTS; i++)     x = wibble.lastIndexOf('>');   sw.stop();   System.out.println('String first pass: ' + sw + ' seconds');    sw.start();   for(long i = 0; i < NUM_TESTS; i++)     x = wibble.lastIndexOf('>');   sw.stop();   System.out.println('Char first pass: ' + sw + ' seconds');    sw.start();   for(long i = 0; i < NUM_TESTS; i++)     x = wibble.lastIndexOf('>');   sw.stop();   System.out.println('Char second pass: ' + sw + ' seconds');    sw.start();   for(long i = 0; i < NUM_TESTS; i++)     x = wibble.lastIndexOf('>');   sw.stop();   System.out.println('String second pass: ' + sw + ' seconds');    //Compiler warning said x was never read locally.. this is to   //ensure the compiler doesn't optimize 'x' away..   System.out.println(x);  } 

Output

Starting perfo test --perfo test with 100000000 iterations-- String first pass: 8.750 seconds Char first pass: 6.500 seconds Char second pass: 6.437 seconds String second pass: 8.610 seconds 63

Conclusion

The version with a char is about 25% faster, but both versions execute very quickly so it probably won’t ever be a bottleneck in your code.