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From garydgregory <...@git.apache.org>
Subject [GitHub] commons-lang pull request: General cleanup
Date Wed, 02 Mar 2016 08:46:41 GMT
Github user garydgregory commented on the pull request:

    https://github.com/apache/commons-lang/pull/127#issuecomment-191131937
  
    Sadly, this kind of change is not a "Good Thing":
    
    @@ -7266,14 +7245,14 @@ public static int indexOfDifference(final CharSequence... css)
{
             // find the min and max string lengths; this avoids checking to make
             // sure we are not exceeding the length of the string each time through
             // the bottom loop.
    -        for (int i = 0; i < arrayLen; i++) {
    -            if (css[i] == null) {
    +        for (CharSequence cs : css) {
    +            if (cs == null) {
                     anyStringNull = true;
                     shortestStrLen = 0;
                 } else {
                     allStringsNull = false;
    -                shortestStrLen = Math.min(css[i].length(), shortestStrLen);
    -                longestStrLen = Math.max(css[i].length(), longestStrLen);
    +                shortestStrLen = Math.min(cs.length(), shortestStrLen);
    +                longestStrLen = Math.max(cs.length(), longestStrLen);
                 }
             }
    
    That is because the compiler converts use an Iterator to traverse an array with a for-each
loop which is slower than traversing it with index access. Rule of thumb: don't use for-each
over an array when performance matters. In low-level libraries like Commons, performance usually
matters.
    
    Please review your patch and remove such changes.
    
    Thank you!


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