Strings and Things - Java - page 91

}

}
System . out . println ( sb2 );

The first method uses the StringBuilder.length() method, so it will only work correctly
when you are starting with an empty StringBuilder . The second method relies on calling
the informational method hasMoreElements() in the Enumeration (or hasNext() in an
Iterator , as discussed in Using Iterators or Enumerations for Data-Independent Access )
more than once on each element. An alternative method, particularly when you aren't start-
ing with an empty builder, would be to use a boolean flag variable to track whether you're at
the beginning of the list.

Processing a String One Character at a Time

Problem

You want to process the contents of a string, one character at a time.

Solution

Use a for loop and the String 's charAt() method. Or a “for each” loop and the String 's
toCharArray method.

Discussion

A string's charAt() method retrieves a given character by index number (starting at zero)
from within the String object. To process all the characters in a String , one after another,
use a for loop ranging from zero to String.length()-1 . Here we process all the characters
in a String :

strings/StrCharAt.java

public public class class StrCharAt StrCharAt {

public public static void main ( String [] av ) {

String a = "A quick bronze fox lept a lazy bovine" ;
for

static void

for ( int int i = 0 ; i < a . length (); i ++) // Don't use foreach

System . out . println ( "Char " + i + " is " + a . charAt ( i ));