Class java.lang.String
  • Concatenation of strings: 
    String str = "d = "+String.valueOf(d)+"cm.";
  • Getting single chars out of the string: 
    char c= str.charAt(0);
  • Methods never change the object itself but return a new instance of String. Example for removing leading and following whitespaces: 
    String text = "  Hallo  ";
String result = text.trim();
System.out.println("Text:"+text+".");
System.out.println("Result:"+result+".");
    Output: 
    Text:  Hallo  .
Result:Hallo.
    • Java Tutorial - Standard Classes Jens Trapp, 1997