The traditional for-loop always uses a loop index - an integer that identifies each iteration of the loop. Loop indexes have always been a fruitful source of error. For example, off-by-one errors are very common in programming, and they are often related to these loop indexes. In addition, the (rather unnatural) computer science tradition of starting loop indexes from 0 instead of from 1 is a continual source of trivial errors.

Since they are more error prone, for-loops should generally be avoided.

Example

import java.util.*;

/** Different iteration styles. */
public class IterateNoIndex {
   
  /** 
  * Iterating without an index is more compact and less 
  * error prone. 
  */
   public void withoutIndex(){
     //for-each loop is usually preferred
     List<String> trees = Arrays.asList("Maple", "Birch", "Poplar");
     for(String tree: trees){
       log(tree);
     }
     
     //Iterators are not as compact as a for-each loop
     Iterator<String> iter = trees.iterator();
     while (iter.hasNext()) {
       log(iter.next());
     }
   }
   
   /** Iterating with an index is more error prone. */
   public void withIndex(){
     //traditional for-loop
     for(int idx=0; idx < 10; ++idx){
       log("Iteration...");
     }
   }
   
   // PRIVATE
   private void log(String aMessage){
     System.out.println(aMessage);
   }
}