몇가지 유용한 코드입니다..

package myTest;
 
public class Test {
  public static void main(String[] args) {
    String s = "This is my test string.";
 
    for (char c : s.toCharArray()) {
      System.out.print(c);
    }
    System.out.println(" ");
 
    for (char c : s.toCharArray()) {
      if ( c == ' ') 
        continue;
      else
        System.out.print(c);
    }
    System.out.println(" ");
 
    for (char c : s.toCharArray()) {
      int ascii = (int)c;
      if ( ( ascii >= 65 &amp;&amp; ascii <= 78 ) || ( ascii >= 97 &amp;&amp; ascii <= 110 ) ) {
        System.out.print(c);
      }
    }
    System.out.println(" ");
 
    for (int i=0; i<s.length(); i++) {
      if ( i % 2 == 0 ) {
        System.out.print(s.charAt(i));
      }
    }
    System.out.println(" ");
  }
}